I. The Cost of Secular Education

The high cost of yeshiva tuition remains a significant challenge to many in the community. Artificial Intelligence (AI) promises a potential solution: it can reduce costs while simultaneously improving the education. Personalized instruction without the staff overhead make AI a potential game changer for yeshiva secular studies, provided it is designed properly.

For example, AI-based tools can provide personalized learning programs, giving each student their own content and learning pace. Where a human teacher may be responsible for dozens of students, AI can deliver individualized instruction simultaneously to all, with a teacher overseeing many classes as a supervisor and supplemental resource rather than as the primary educator. This technology would dramatically lower the need for staff, allowing schools to reduce payroll, the single largest driver of tuition costs.

It remains to be seen whether AI can serve effectively as a teacher. We must also ask whether halakhically we are allowed to use it in this function.

II. Teachers and Yeshiva Education

The Talmud (Avodah Zarah 15b) rules that one may not send a Jewish child to a gentile teacher. The reason for this prohibition is debated by commentators. Rambam (Mishneh Torah, Hilkhos Issurei Bi’ah 22:5) explains that the concern is primarily that gentile teachers in the ancient world were free to physically abuse Jewish students. If that danger is absent, Rambam implies, the prohibition does not apply. Rashi (ad loc., s.v. ve-ein mosrin lahem), however, presents a dual concern: not only the possibility of physical harm but also the spiritual danger that the teacher might influence the child to stray from traditional Jewish belief and practice. According to Rashi, the concern for indoctrination remains even if physical abuse is no longer an issue.

Rav Moshe Isserles (Rema; Yoreh De’ah 153:1) follows Rashi, which the Vilna Gaon (glosses, ad loc.) explains is because the concern about improper influence persists. Rav Shmuel of Furth, in his Beis Shmuel commentary on Shulchan Arukh (Even Ha-Ezer 22:7), argues that Rav Yosef Karo likewise follows Rashi. Thus, we find a critical disagreement: Rambam permits gentile teachers under conditions of safety, while Rashi maintains the prohibition due to the risk of ideological influence. Modern authorities follow Rashi’s strict view.

This seems to mean that yeshiva day schools should be forbidden to employ gentile teachers for secular subjects. And yet this is common practice. The explanation, I believe, lies in the difference between the ancient model and the modern school system. In Talmudic times, a child was sent to a teacher who functioned independently, teaching according to his own ideas. Such an arrangement raised both dangers outlined by Rambam and Rashi. Today, by contrast, secular teachers are employed within institutional frameworks. The yeshiva sets the curriculum, supervises instruction and enforces proper behavior. Teachers may not introduce ideological material outside of the approved syllabus.

I have found little discussion of this topic among the major halakhic authorities. The earliest I had found is Rav Akiva Schlesinger, in his 19th century polemic, Lev Ha-Ivri (vol. 1, p. 29n1). In his opposition to non-Orthodox Jews, Rav Schlesinger argues that those who are legally obligated to provide secular studies should hire gentile teachers rather than non-Orthodox Jews because the latter will be more likely to proselytize. In a footnote, he points out the Talmudic prohibition and argues that it only applies when a child goes to the teacher’s home or school to study. But when the teacher comes to the Jew’s home or to a Jewish school, it does not apply.

Rav Avraham David Horowitz (20th cen., Israel) reached an even more lenient conclusion. He argues that the prohibition only applies when there is a concern that a teacher will taint his class with his personal beliefs. However, if a secular school maintains standards and professionalism, a Jewish student may attend without concern (Kinyan Torah Ba-Halakhah, vol. 1, no. 55, par. 7). Of course, nowadays secular universities allow professors free reign to dilute their courses with their secular ideologies so no such permission remains.

Jewish day schools do not allow professors to inject their personal beliefs into the classroom. The Jewish studies faculty serves as role models and life guides while the secular studies faculty is there to teach the syllabus. This practice would halakhically justify the common practice of Jewish schools hiring gentile teachers for secular studies. However, those schools that, in the name of academic freedom, do not restrain their teachers would presumably fall under this prohibition.

III. AI as Secular Teachers

When applied to AI, this distinction becomes critical. According to Rambam’s view, an AI program cannot physically harm a child. The central concern—violence—does not exist. Therefore, Rambam’s framework would support permitting AI to serve as a secular studies instructor. According to Rashi’s approach, the concern of ideological influence remains. While AI has no beliefs of its own, its training data and algorithms may embed non-traditional or secular worldviews into its functioning. These could subtly shape a student’s thinking, precisely the concern Rashi articulated. On this basis, an unsupervised AI would be prohibited. Since the Rema codifies Rashi’s emphasis on ideological influence, the halakhic presumption is that AI instruction would be forbidden unless adequate safeguards are in place.

However, if supervision addresses the concerns with gentile teachers, it should likewise address the risks of AI. An AI system can be restricted through technical and educational “guardrails.” Programmers can filter its content, block religious or ideological commentary, and confine its role to secular subjects such as mathematics, science or language. It can even push it in the direction of traditional Jewish beliefs, forcing the AI to adopt an Orthodox viewpoint. In addition, rabbinic and educational supervisors can test the system’s outputs to ensure conformity with traditional Jewish standards. In fact, AI may present fewer risks than human teachers. While human instructors inevitably bring personal worldviews into the classroom, AI can be explicitly designed and constrained. It lacks independent agency. Thus, when properly programmed and supervised, AI arguably offers a safer and more controllable means of delivering secular education.

For yeshivos under pressure to contain tuition costs, this understanding opens a significant opportunity. If AI can be implemented with the necessary safeguards, not eliminating secular teachers but reducing the head count significantly, schools may deliver secular education more effectively at far lower cost. This could alleviate the crushing burden on families while preserving the high standards of Torah education. By investing in oversight and careful design, the community can reduce the financial burden while enhancing commitment to tradition.

OpenAI recently released ChatGPT-5, which faced a number of public challenges. One of its features is that users can now choose from five preset Artificial Intelligence (AI) “personalities.” The list of personalities includes cheerful and adaptive; thoughtful and supportive; exploratory and enthusiastic; efficient and blunt; and, most provocatively, critical and sarcastic. In other words, you can now speak to an AI designed to respond with skepticism, sarcasm and biting commentary.

This raises an ethical and halakhic question. If AI is only code generating text, do its character traits matter? Or can it subtly influence us, shaping how we speak and even how we think?

I. Growth and Influence

Human beings are social creatures who continually evolve, with their thoughts and actions shaped in part by the company they keep and the models they observe. In order to grow in the right direction, we must surround ourselves with positive role models. Rambam vividly explains the proper attitude to this psychological reality (Mishneh Torah, Hilkhos De’os 6:1):

“It is natural for one’s character traits (de’os) and actions (ma’asim) to be influenced by friends and companions and for one to follow the local norms of behavior. Therefore a person must associate with the righteous and constantly sit with the wise in order to learn from their deeds. And he should distance himself from the wicked who walk in darkness so that he will not learn from their deeds.”

This statement is not just general guidance but has specific practical implications. For example, Rav Shlomo Aviner (cont., Israel) writes in a responsum that Israelis should not spend extended time in India after their army service because, among other reasons, it involves being in close quarters with non-religious and non-Jewish people whose behaviors can have a profound negative influence (Responsa She’eilas Shlomo 4:246). Similarly, Rav Shlomo Min Hahar (20th cen., Israel), in his 1971 halakhic guide for IDF soldiers (Dinei Tzava U-Milchamah, par. 5) cautions that they should not spend downtime with non-religious soldiers because of the potential impact on their spiritual character.

However, a subtle shift in Rambam’s language might have significant relevance for our question. He begins with both de’os and ma’asim—attitudes, dispositions, character traits and deeds, behavior, actions. He concludes that we must keep company with the righteous and avoid the wicked because of their deeds. Why the move from traits to behaviors?

II. The Power of Traits

Given the context of Hilkhos De’os, which discusses the proper character traits, it is difficult to sustain the argument that halakhah primarily governs what we do, not what we silently feel. It seems more likely that Rambam frames the issue in behavioral terms because character traits are abstract until they appear in conduct. A selfish attitude becomes contagious when it is displayed in action. It is true that we must be worried about adopting the unhealthy character traits of those who surround us. However, Rambam highlights actions because generally they are the vehicle through which traits spread.

Alternatively, perhaps Rambam feels that from a practical standpoint, we need only be concerned with being influenced by other people’s concrete bad deeds and not their intangible attitudes. We cannot be influenced materially by the thoughts inside other people’s hearts. Our focus must be on maintaining positive deeds, which will in turn sustain positive attitudes. If we take care to avoid unhealthy actions, we will avoid being influenced by other people’s negative character traits.

This last approach raises the important question: if Rambam focuses on actions, does that mean that we need not worry about being influenced by other people’s traits if they are not translated into action?

The Gemara (Shabbos 33a) teaches that one who merely hears nibul peh, vulgar or profane speech, is punished. He himself did not speak improperly. However, the words alone, encountered passively, carry moral harm. This text implies that exposure to speech itself, without physical action, can corrode character. Even language divorced from deed conveys a personality trait and influences the listener. If vulgar speech damages, then cynicism, sarcasm or arrogance transmitted in words can also damage.

III. AI and Character

With this in mind, we can return to our discussion of AI personalities. A human being has both traits and behaviors with influence often flowing through deeds that then shape traits. An AI chatbot has no deeds; it does not act in the world. Its entire presence is in speech.

This means that the danger lies not in AI’s actions, because it has none, but in its simulated traits. An AI cynic models cynicism. An AI with a sharp tongue normalizes sarcasm. A dismissive or arrogant personality slowly habituates its users to those same traits.

Must we worry about AI’s corrosive influence on character traits? This seems to depend on how we understand Rambam’s shift in language from de’os and ma’asim, traits and actions, to just ma’asim, actions. If we believe that Rambam is concerned for both but focuses on actions because generally that is how attitudes are transmitted, then we must avoid a chatbot’s corrosive speech. On the other hand, if Rambam only warns us about learning from others’ negative deeds because attitudes are not transmittable, then we need not be concerned about an AI chatbot’s personality.

A third possibility is that speech constitutes action. Traditionally, there is a debate whether speech rises to the level of action. For example, the Torah forbids muzzling a working animal to prevent it from eating (Deut. 25:4). If you effectively muzzle an animal by verbally berating it, R. Yochanan says you violated the prohibition through speech while Resh Lakish says that speech does not constitute action (Bava Metzi’a 90b). Tosafos (ad loc., s.v. R. Yochanan) quote a number of relevant texts regarding whether speech constitutes action and conclude that speech constitutes action if it yields tangible results, like an animal refraining from eating. In our case, it seems farfetched to say that an AI’s words lead to action and therefore that the speech constitutes action.

IV. Practical Implications

The upshot is that creators of AI tools, particularly but not exclusively for Jewish use, must design them to speak with derekh eretz and kavod, manners and respect. AI must model responsible behavior so it becomes a positive, and certainly not a negative, influence.

When this is not the case, according to one reading of Rambam, we are instructed to distance ourselves from bad influence. Choosing a sarcastic or cynical AI personality is no different from choosing friends who mock and belittle. Even if the AI is only computer code, the influence of its words is real. Interacting daily with an AI cynic or a sarcastic assistant risks habituating yourself to bad traits. This is not harmless fun; it is a steady shaping of character.

Rambam writes above that “a person must associate with the righteous and constantly sit with the wise.” Today, that advice applies not only to our neighbors and friends but also to the personalities we allow into our lives electronically. AI can be a tool for Torah and personal growth but only if it speaks with dignity and refinement. Otherwise, it becomes a daily tutor in bad midos.

Artificial Intelligence (AI) is changing how we approach complex problems across a wide range of fields. From diagnosing rare diseases to reconstructing lost languages, AI has proven itself capable of analyzing vast amounts of data, detecting patterns and offering insights that human researchers might miss. Perhaps there is room to ask whether AI could help solve a very intricate and complex religious question: can it determine the exact location of the mizbe’ach, the altar in the Beis Ha-Mikdash, the holy Temple in Jerusalem?

At first glance, the question seems technical. Feed AI everything we know from the Bible, Sages, commentators, ancient and medieval attestations, and archaeological surveys, and let it find patterns and connect information in order to identify the precise location. Many researchers have attempted to do this over the past century, yielding conflicting results. Perhaps AI can reach a conclusive determination that satisfies all parties. However, halakhah is not always governed by evidence alone. Sometimes it demands a specific type of certainty, one rooted not in analysis, but in tradition or prophecy. The placement of the mizbe’ach may be such a case.

I. A Fixed and Holy Location

The mizbe’ach is not just another vessel in the Temple. Its location is permanent, not subject to change. The Rambam writes: “the altar’s place is very precise which may never be changed” (Mishneh Torah, Hilkhos Beis Ha-Bechirah 2:1). This spot is the same location where Adam brought his sacrifice, where Noach offered sacrifices after the Flood, where Avraham built the altar at the Akeidah and where David and Shlomo ultimately built the Temple (ibid., 1-2).

The Talmud (Zevachim 62a) emphasizes the need for precision in placing the altar, ruling that it must be built on its exact location. This is not merely a preference for historical continuity, but a halakhic requirement embedded in the sanctity of the site. Building the mizbe’ach even slightly off-site would invalidate the sacrifices offered on it.

II. Prophetic Identification

How was the correct location identified? The Bible describes how the prophet Gad instructed King David to purchase the threshing floor of Aravna the Jebusite and build an altar there (1 Chron. 21:18–30). This episode is not simply a historical footnote, but rather serves as the halakhic basis for the location of the Temple. Rambam’s citation of this story emphasizes that the placement of the mizbe’ach was confirmed through prophecy.

In 1862, Rav Tzvi Hirsch Kalischer published his Derishas Tziyon, in which he advocated for the immediate resumption of sacrificial worship. In the third essay (part 1, par. 2, p. 91 in the 2002 edition), Rav Kalischer says that Rav Akiva Eiger asked him how we can know where the altar should be if in the past they needed prophets for that. Rav Kalischer replied that we can measure from the Western Wall and recreate the Temple based on the Mishnah tractate Midos.

Rav Kalischer’s colleague, Rav Eliyahu Guttmacher, challenged him that we need a prophet to identify the place for the altar (p. 134). Rav Kalischer replied that the prophecy was needed not to identify the place of the altar but because they wished to expand the altar and needed the prophet’s instruction how to do that. However, reconstructing the altar itself requires only knowledge of its past place. Rav Yechiel Michel Tukaczinsky answers more simply that King David did not know where the altar should be built and require a prophet to show him. If we can determine the proper place without a prophet, we are allowed to build the altar on our own (Ir Ha-Kodesh Ve-Ha-Mikdash, vol. 5, ch. 6, par. 7, p. 67).

Rav Yaakov Ettlinger argues with this view (Binyan Tziyon, no. 1). He contends that even if we know the exact site of the altar, we need prophetic permission to offer sacrifices there. Many others follow suit, making this the majority, mainstream view (see Rav J. David Bleich, Contemporary Halakhic Problems, vol. 1, pp. 259-262). According to this approach, we cannot rebuild the altar or the Temple, nor offer sacrifices, without the instruction of a prophet.

III. Prophecy or Evidence?

Particularly since the Six Day War’s reconquest of the Temple Mount, many studies have been published attempting to determine the location of the Temple, with conflicting conclusions. AI could potentially play a significant role in resolving any doubts that remain. Its capacity to synthesize texts, analyze spatial data and correlate seemingly unrelated pieces of evidence makes it uniquely suited to the task of finding the right spot. AI could process all references to the Temple Mount in rabbinic literature, compare descriptions across centuries, overlay historical maps with modern satellite images and match archaeological findings with textual data. Such a system might determine the precise location of the altar relative to other fixed points. It might even be able to reconstruct a highly plausible model of the Second Temple and superimpose it on the current Temple Mount. In a purely analytical sense, AI could offer the most precise determination ever produced. But even if its conclusions are correct, are they halakhically actionable?

According to Rav Kalischer, AI can help us sort through the information and make a detailed plan for the altar and the Temple. All we need is certainty, whether it comes from prophecy or analysis. However, according to Rav Ettlinger, prophecy is needed to rebuild the altar. Even the most advanced AI cannot resolve the halakhic uncertainty and offer us permission. Halakhah might treat all AI conclusions as impressive but ultimately insufficient. According to this approach, neither history nor science, archeology nor architecture, can allow us to build the altar.

IV. Recreating Halakhic Items

This tension between evidence and authority might be broader than reconstructing the Temple architecture. For example, a comparable debate exists regarding the identification of tekheiles, the colorful dye used in tzitzis. After centuries without it, some contemporary researchers have argued that the chilazon, the sea creature that produces the dye, has been rediscovered in the murex trunculus.

Many halakhic authorities, including Rav Hershel Schachter and Rav Yisrael Belsky, accept this identification based on strong scientific and textual evidence. However, other authorities, including Rav Joseph B. Soloveitchik, are reluctant to endorse the use of tekheiles without an unbroken tradition (Nefesh Ha-Rav, pp. 53-54). They argue that empirical identification, no matter how convincing, does not carry the same halakhic weight as tradition. This is particularly true when arguing based on evidence that is largely circumstantial, attempting to correlate contemporary facts to ancient descriptions. While AI may offer valuable tools to support the investigation of halakhic items, its conclusions will be bound by the limits of evidence-based research.

For those who believe that the location of the altar can be determined empirically, AI may help decisively show us how and where to build it. But for those who maintain that only prophecy can permit the rebuilding, no algorithm can replace a prophet. According to this view, AI might help us look back with clarity, but only prophecy can help us move forward with certainty. In the end, AI may clarify what we know, but it cannot authorize what we do.

Seeing is believing, until that too is taken away from us. The rapid development of artificial intelligence (AI) has produced powerful new tools, among them the ability to create “deepfakes,” which are highly convincing but entirely fake images, audio recordings or videos of real people. A politician may appear to endorse a controversial policy, a rabbi might seem to utter heretical ideas or a teacher could be seen acting inappropriately but it is all through manipulated media. These synthetic creations are increasingly difficult to distinguish from reality and pose serious ethical and halakhic questions, and paradoxically might also offer a solution to a difficult social problem.

I. Libelous Content

Let us begin with the most obvious victim: the individual whose likeness is misused. If a deepfake attributes scandalous or false words to a person, this constitutes classic hotza’as shem ra, false speech. Rav Yisrael Kagan (20th cen., Russia) quotes Onkelos (Lev. 19:16), who translates “Do not be a talebearer” as “lo seichol kurtzin.” Rashi (ad loc.) explains that this refers to the way gossippers motion with their eyes. Even indirect gossip, even mere motioning without any words, qualifies as forbidden lashon ha-ra (Chafetz Chaim 1:1:8 n. 13). As it says in Mishlei (Prov. 6:12-13), “A base person… winks with his eyes, scrapes with his feet, points with his fingers.” Lashon ha-ra does not have to be actual words. Posting an image or a video accusing someone of a misdeed constitutes forbidden speech, even if it is not verbal.

Hurtful content goes further. Posting a video that hurts someone’s feelings or damages someone’s reputation is a form of attack. This is biblically prohibited as ona’as devarim, hurtful and damaging speech (Bava Metzi’a 58b). You may think that this only applies to a verbal insult or attack–after all, “devarim” means words. However, the Torah (Lev. 25:17) merely says “lo sonu” and does not differentiate between methods of delivering this harm. When someone is portrayed doing or saying something inappropriate through a deepfake video, it violates their reputation and causes social, professional and emotional harm. Even if the victim is ultimately vindicated, the damage may already be irreversible.

II. Theft of a Likeness

There is also the question of image rights. Do I have halakhic control over my likeness? Rav Yosef Chaim Sonnenfeld (20th cen., Israel) did not object to people being photographed without consent, arguing that it causes no tangible damage (Salmas Chaim, no. 475). In contrast, Rav Menashe Klein (20th cen., US) contends that unauthorized photography may be prohibited because a person’s image has commercial and personal value. He notes that celebrities sell their likenesses, and therefore, using someone’s image without permission can constitute a form of theft (Mishneh Halakhos 7:117). Rav Simcha Yonah Klein (cont., England) follows Rav Sonnenfeld’s view but adds an important caveat: even the lenient view forbids publicizing damaging images (Piskei Ha-Mishpat 363:14).

Rav Shlomo Aviner (cont., Israel) takes a more fundamental approach, invoking the verse, “ve-ahavta le-rei’akha kamokha” (Lev. 19:18), which means that you must treat others as you would wish to be treated (Shabbos 31a). If a person finds it offensive or degrading to have his picture used without consent, that alone may be grounds for objection (Piskei Shlomo, vol. 3, pp. 146-147).

A deepfake is not merely a picture but a full impersonation, crafted to deceive and often to defame. The halakhic violations here are compounded: falsehood, humiliation, possible theft and an affront to human dignity.

III. Misleading the Public

While the subject of the deepfake suffers personal harm, halakhah also recognizes the broader concern of deceiving the public. The Talmud (Chullin 94a) prohibits geneivas da’as, deception. Rashi explains that misleading someone, even without causing financial loss, is forbidden. Even pretending to do someone a favor, when you really did it for personal reasons, is forbidden. Rambam (Mishneh Torah, Hilkhos De’os 2:6) offers other examples of deceptions that fall under this prohibition. The Torah says, “mi-dvar sheker tirchak, stay far away from falsehood” (Ex. 23:7). We are forbidden not just to lie but even to approach the point of generating falsehood.

Beyond personal injury, deepfakes pose broader communal dangers. When a large audience sees a fabricated video of a community leader making a controversial statement or a public figure endorsing a problematic idea, they are victims of falsehood. The consequences can reverberate in practical decisions and personal attitudes. In the past, we have seen disinformation sway public debates. Deepfakes could do the same on a much larger scale.

The implications are troubling. The erosion of trust in public communication affects not only our perception of individuals but also our confidence in halakhic, political, educational and journalistic institutions. When people begin to question the authenticity of everything they see, even genuine content becomes suspect. That social instability undermines public discourse. While a defamed individual suffers acutely, the collective deception may be more insidious. It destabilizes communal norms and damages the integrity of public discourse.

IV. A Silver Lining

Despite these serious concerns, the deepfake phenomenon may inadvertently contain a silver lining. Deepfakes might ultimately prompt society to think more critically about information. As people grow aware that images, videos and audio can be manipulated, they may become more discerning: Who recorded this? Where was it published? Has it been verified?

This shift could lead to a decline in so-called citizen journalism, i.e. social media reporting, and a resurgence of serious journalism. Media outlets that engage in careful fact-checking, apply editorial oversight and maintain transparent sourcing may gain renewed relevance. In an environment dominated by outrage and virality, credibility may once again become a competitive advantage.

For years, media has been pulled by the gravity of outrage and speed, chasing clicks and engagement at the expense of accuracy. The deepfake crisis may reverse that trend by incentivizing credibility over virality. In doing so, it would return media to its original mission: not to provoke, but to inform; not to inflame, but to illuminate.

Artificial Intelligence (AI) is increasingly shaping our world, raising new and complex questions. One such issue is whether it is permissible to use AI tools that analyze email and message content in order analyze trends without obtaining individual information. Consider an AI tool that reads people’s direct messages to analyze business trends and advises you on investment strategies. This tool can be perfectly legal but halakhah might be stricter. Are we allowed to benefit from AI analysis of private emails and messages?

I. The Cherem of Rabbeinu Gershom

Rabbeinu Gershom (11th cen., Germany) gathered leading rabbis together to issue a cherem—a communal ban—against a number of practices. Historians debate his specific role and the exact content and list of practices that fell under this ban, as opposed to later bans (Chakmei Ashkenaz Ha-Rishonim, p. 132ff). Regardless, there is a long-standing ban against opening and reading someone else’s mail that is widely attributed to Rabbeinu Gershom. The original context was physical letters, but authorities have extend its application to modern communication, including emails and text messages.

Rav Simchah Yonah Klein (cont., England) writes that the cherem applies even to hidden video cameras, i.e. nanny cams (Piskei Ha-Mishpat 154:7). Similarly, Rav Shaul Alter, in his recent book Software and Artificial Intelligence in Halacha, writes that “the cherem is not limited specifically to reading a letter, but to consuming any information that was not intended for public knowledge” (p. 334). It seems clear that emails and private messages fall under the cherem, as well.

Rav Chaim Palaggi (19th cen., Turkey) asks what rationale lies beneath this cherem? Even if the act is independently prohibited, Rabbenu Gershom and his colleagues may have enacted a cherem to reinforce the prohibition. Rav Palaggi suggests that it might be the obligation to love your fellow like yourself, or rather to not do to others what you would not want done to you (Lev. 19:18; Shabbos 31a). It might be a variant of gossip-mongering (Lev. 19:16). Alternatively, it might be a form of deception, geneivas da’as, or of using someone’s property without permission, which constitutes theft (Responsa Chikekei Lev 1:49). The distinctions between these different rationales will be crucial for evaluating the permissibility of AI that accesses private communications.

II. Rationales and Implications

Some authorities understand the prohibition as a form of theft by accessing someone else’s property, his information. Rav Chaim Shabesai (17th cen., Greece) writes that opening someone else’s letter is like borrowing something without permission, which is a form of stealing (Responsa Toras Chaim 3:47). In his recently republished book, The Practical Torah, Rav Michael Taubes writes that according to this view, “such action is forbidden even for the purpose of a mitzvah, particularly since one can cause damage to another by revealing his secrets” (p. 297).

According to this approach, if an AI accesses private email data without the owner’s consent, then the developers or users of the AI tool may be considered to have committed a form of theft. Even if no human sees the content, the act of extracting value from someone’s private correspondence without permission would still fall under the category of theft.

On the other hand, several authorities understand the core of the cherem not as theft, but as a violation of privacy. Rav Ya’akov Chagiz (17th cen., Morocco) briefly says that opening someone else’s mail violates the prohibition against gossip-mongering (Halakhos Ketanos 1:276). As mentioned above, Rav Chaim Palaggi suggests that this might be a violation of loving your fellow as yourself. However, both of those reasons would permit opening someone else’s mail when there is a mitzvah need to do so.

According to this approach, the violation is not the act of accessing information per se, but the act of disclosure. Meaning, the problem is violating the privacy of the individual. If so, an AI system that ingests an email but does not reveal the content, only extracting patterns or offering aggregate insights, does not violate the individual’s privacy. The secret remains hidden; no human sees it, no one exposes it.

For example, if an AI reads a team’s emails and determines that a particular merger will go through, but does not expose the personal content of any individual message, it might be functionally equivalent to a locked diary read by no one. The information is accessed, but the individual’s personal privacy remains intact.

III. Additional Considerations

According to our analysis, if reading someone’s mail is forbidden because of gossip-mongering, an AI would be allowed to analyze private correspondence and provide anonymized and aggregated analyses which could be used for business purposes. However, if it is prohibited because of theft, then even anonymizing and aggregating the information would still be forbidden.

However, Rav Yosef Shalom Elyashiv (21st cen., Israel) is reported as modifying Rav Palaggi’s analysis in a significant way. Rav Elyashiv’s son-in-law, Rav Yitzchak Zilberstein, presented a related question to him. Rav Elyashiv replied that opening someone’s mail can only constitute theft if the information is used to interfere with the victim’s plans. But if the victim does not suffer any loss, he has not been subjected to theft (Chashukei Chemed, Yoma, p. 55). If that is the case, then we would be allowed to invest based on advice legally extracted by AI from private emails and correspondence as long as it does not cause any damage to other investors.

I. AI and Video Supervision

As artificial intelligence (AI) makes its way into the workforce, it is worth asking whether it can serve as a mashgiach, a kosher inspector. While in the future there may be AI robots that can visit restaurants and factories, we do not have to look ahead to consider this question. Already today, many factories and restaurants are equipped with video cameras that enable remote supervision. During Covid, the use of such surveillance became even more widespread.

One problem with video surveillance is that it requires someone to watch the camera feeds, which can become a significant challenge as kosher supervision cameras proliferate. AI may offer a solution to this problem. Can AI be trusted to inspect the camera feeds and certify that nothing improper occurs at the establishments under supervision?

AI technology paired with live video feeds has already become a valuable tool in general surveillance. It monitors activity, detects anomalies and provides real-time data on temperature, movement and workflow. In fact, it can also monitor other electronic information about food production, such as ingredient ordering and delivery schedules. AI can even reduce human error or alert to suspicious behavior. However, kosher inspection involves more than monitoring.

A mashgiach must be aware of the broader context: how ingredients are sourced, how utensils are maintained and how personnel follow halakhic restrictions. Nothing can replace an in-person inspection. A simple conversation with employees reveals a lot about the professionalism of the operation, unexpected changes that have happened or are about to happen, and general information about personnel and processes. Additionally, cameras can be manipulated and visual access may not capture essential details.

Be that as it may, there still is room for AI to serve as the video mashgiach that works alongside human inspectors. Is AI halakhically trusted for this work?

II. Mashgiach: Testimony or Trust?

Very often, a mashgiach is not permanently stationed at a factory or restaurant. He comes and goes periodically (yotzei ve-nikhnas), conducting spot checks. The halakhic mechanism that allows yotzei ve-nikhnas is the concept of mirsas, fear. Namely, the workers do not violate proper procedures because they fear being caught by the mashgiach on a spot check or on a video stream. This fear serves as a deterrent and ensures compliance.

When a mashgiach affirms a factory’s procedures, is he testifying to the kosher status of the food? If he has not witnessed the food’s production, it is not clear whether he can testify to that. Perhaps the concept of mirsas enables the mashgiach to testify even when he does not see the entire production. Or, alternatively, it eliminates the need for testimony altogether, allowing the mashgiach to simply report facts on the ground. Put differently, is the mashgiach testifying about the food or is he serving as an agent of the supervising rabbi who testifies about the food? As long as the mashgiach verifies the food production to the satisfaction of the supervising rabbi’s halakhic requirements, the supervising rabbi – whose name appears on the kosher certificate – can testify that the food is kosher. If so, AI can serve as a mashgiach.

On the other hand, if a mashgiach is considered a witness, then the laws of testimony for forbidden foods apply. Only an observant Jewish adult can serve in such a capacity. A gentile, a child or someone lacking halakhic competence is disqualified. AI, which lacks personhood and obligation in mitzvos, would certainly be excluded on these grounds.

III. Women and AI

The question of AI as a mashgiach can be informed by the halakhic discussion about whether women can serve in kosher supervision. Rav Moshe Feinstein (20th cen., US) argues that a woman may serve as a kosher supervisor (Igros Moshe, Yoreh De’ah 2:44). Rav Feinstein addresses two concerns: 1) is a woman’s testimony accepted in complex kosher matters? To this, he answers yes. 2) Can a woman serve in a communal position of authority? To this, Rav Feinstein answers no but suggests that she appoint a supervising rabbi to formally issue the kosher certificate while she serves as the kosher inspector.

Can this model work for AI also? It seems not, because Rav Feinstein still requires the woman inspector to testify to the supervising rabbi about the food’s kosher status. However, Rav Feinstein opens the door to a different framework. In the directly preceding responsum (op cit., 43), he writes that in many practical areas of kashrus, we rely not on formal testimony but on ne’emanus – the halakhic assumption of trustworthiness. When someone is known to be honest and trustworthy, halakhah allows reliance on their word even without the structure of testimony (Igros Moshe, Yoreh De’ah 2:43). If so, then maybe even AI can be relied upon even if the mashgiach testifies to the food’s kosher status. A well-trained AI, thoroughly tested and validated, may be even more trustworthy than a human because it has no personal interests or distractions that might compromise its judgment.

If so, it seems that when it comes to monitoring video feeds, AI can serve as a kosher inspector that provides important information for the consideration of the supervising rabbi. This is true assuming that the AI has been tested and verified as an accurate inspector of videos. This also assumes that a separate inspector makes site visits to review other pertinent information.

Potentially, AI is a powerful tool of kosher supervision. It can inspect important parts of the kosher food production process. However, currently it cannot replace the site visit and merely supplements the visit with the monitoring of electronic surveillance.

Lawsuits are in progress about whether AI developers infringe on the rights of content creators when training models on copyrighted material. If my book, Articles of Faith: Traditional Jewish Faith in the Internet Era, is among the trillions of points of data used, for example, to train ChatGPT, do I have a copyright claim? That question is now before the US courts. I would like to discuss here a different issue. Do you, the user, violate AI’s copyright by using its content without attribution? On this question, I suspect that Jewish law is stricter than American law.

I. Copyright

ChatGPT does not retain copyright over its outputs. Its terms of use explicitly state: “We hereby assign to you all our right, title, and interest, if any, in and to Output.” Similarly, Anthropic’s terms for Claude say: “Subject to your compliance with our Terms, we assign to you all of our right, title, and interest—if any—in Outputs.” Under American law, this appears to settle the matter. Granted, if a court later determines that these models were trained in violation of copyright, that could retroactively affect users’ rights to the outputs. Barring that, there is no other legal issue in taking the AI’s outputs and signing your name to it unless you are specifically told to create original content (e.g. a homework assignment).

This is significant within halakhah, where there are two primary views on copyright. According to Rav Nachum Menashe Weisfish, in his Copyright in Jewish Law, the majority opinion believes that halakhah grants intellectual property rights to content creators. The minority opinion believes that there is no copyright in halakhah beyond the law of the land. In this case, both views would agree that AI holds no copyright, since the developers have explicitly waived it. However, that is not the end of the halakhic discussion.

II. Giving Recognition

Rav Moshe Feinstein (20th cen., US) was asked about cheating on high school Regents exams. He writes that students in school are forbidden from copying answers because of geneivas da’as, misleading others. You are falsely claiming to possess knowledge. If this deception leads to a higher GPA and ultimately employment, Rav Feinstein says that you are stealing from your employer with every paycheck you receive based on false grades. That constitutes actual, ongoing geneivah (theft) in addition to the initial geneivas da’as (Iggeros Moshe, Choshen Mishpat, vol. 2 no. 30).

Rav Chaim Sofer (19th cen., Hungary) was asked whether you may say a Torah insight in the name of a non-Orthodox scholar. He answers that it is improper to do so (as I discuss at length in my book, Articles of Faith, ch. 14). However, he adds that you may not take credit for the insight. Rather, you should say that you heard it from someone else, to avoid stealing intellectual credit (Machaneh Chaim, vol. 3 no. 11).

Similarly, Rav Nachum Menashe Weisfish (op cit., 16:5): “It is prohibited for one to accept undeserved credit. Thus, it is forbidden to relate thoughts of another and claim them as one’s own.” He adds (16:24): “If a person permits others to repeat his thoughts without mentioning his name, then doing so does not constitute theft. However, one may not give the impression of being the originator of the thoughts, as it is forbidden to accept undeserved honor for knowledge, etc., which one does not truly possess.” Applying this to AI, presenting its output as your own misrepresents your knowledge, skills and achievements. This constitutes geneivas da’as and may lead to outright geneivah.

III. Showing Gratitude

Rav Aaron Levine (21st cen., US) takes this further. argues that failing to properly cite sources is not just misrepresentation but also a lack of hakaras ha-tov, gratitude. If you quote a primary source because you saw it cited in a secondary work, you must also credit that secondary source, since it acted as your teacher. Even if you verify the original, the person who led you there deserves acknowledgement. Rav Levine connects this to the teaching in Avos 6:6: “Whoever repeats something in the name of the one who said it brings redemption to the world” (Moral Issues of the Marketplace in Jewish Law, pp. 31-35).

However, AI is not a person to whom you owe gratitude. It is an object, a stick or a stone. Are we obligated to show gratitude to inanimate objects? Perhaps surprisingly, we see unequivocally from midrash that we are, indeed, expected to show gratitude to inanimate objects. In the biblical story of the ten plagues, Moshe does not initiate the first two plagues — water and frogs (Ex. 7:19-20, 8:1-2). The midrash explains that since the Nile protected Moshe as a baby, God insisted that he show gratitude by refraining from punishing the river (Shemos Rabbah 9:10). The same idea applies to the third plague of lice, which started in the dirt in which Moshe hid the Egyptian he killed (Ex. 8:12-13; Shemos Rabbah 10:7). Commentators explain that for the sake of our own character, we must recognize the benefits we receive from inanimate objects and respect them accordingly (e.g. Rav Avigdor Nebenzahl, Sichos Le-Sefer Shemos, p. 19).

IV. Ghostwriting

At the same time, halakhah acknowledges the role of common practice. Ghostwriting is sometimes accepted. I have personally ghostwritten articles for well-known rabbis. These pieces reflected their ideas and were reviewed and approved by them. In such cases, readers understand that extremely busy public figures may employ others to help articulate their thoughts. Within that context and expectation, there is no deception.

But in other contexts, ghostwriting is clearly dishonest. For example, it is not acceptable to submit someone else’s writing for academic credit or for pay without disclosing the actual author. Again, it is a matter of assumptions based on industry standards. When it comes to editing, there is even more room for external help — whether human or electronic.

Ultimately, halakhah takes industry standards and assumptions into account, including regarding AI. If there is no assumption that the stated author actually wrote the words, then there is no concern for theft. With ghostwriters and editors, omission of credit may involve ingratitude but if you pay the author or editor with the understanding that he will not be mentioned, then he waives his right to mention. Since ChatGPT grants permission to use its outputs without attribution, it can be argued that it likewise waives the right to be credited. Nonetheless, unless prevailing norms suggest otherwise, halakhah generally expects users to disclose when content is generated by AI. Of course, norms and standards change over time.

I. Military Encampments in Halakhah

With the recent stunning military success in Israel’s initial attack on Iran, it is an opportunity to celebrate the Israeli Air Force by examining one aspect of its halakhic significance. The Torah has special laws for a military encampment. The question remains what constitutes such a military encampment to be subject to these rules.

The Torah outlines specific requirements for soldiers: “When you go out to encamp against your enemies… Have a designated place outside the camp, and you will go out there to excrete. Have a peg in addition to your weapons; when you need to sit to excrete dig with it, then use it again to cover your excrement. Because the Lord, your God, is moving within your camp to save you and to defeat your enemies before you, so your camp must be holy; let Him not see within you disgraceful objects lest He turn away from you.” (Deut. 23:10-15) In practice, this means that military encampments require bathrooms that are fully surrounded by walls. Otherwise, soldiers must carry digging equipment and relieve themselves outside the camp and cover it with dirt.

In addition to the biblical laws of military encampment holiness, the Mishnah (Eruvin 17a) says that the Sages exempted a military encampment from four rabbinic laws. “1) gathering wood from any place [with no concern that he is stealing wood]; 2) washing of the hands [ritually before eating]; 3) demai [separating tithes from doubtfully tithed produce]; and 4) eruv.” These requirements and leniencies apply only to military encampments as halakhically defined, necessitating a clearer understanding of what qualifies as such.

Do these rules still apply today or do they only refer to ancient armies? Rav Shlomo Ben Tzemach Duran (Rashbatz; 15th cen., Algeria) believes that the biblical law is not about a military encampment per se but about an encampment with the holy ark, which accompanied the ancient Jewish army. The sanctity of the ark requires extra care and cleanliness. Rav Yitzchak of Corbeil seems to write similarly (Semak, nos. 83, 57). However, the anonymous Sefer Ha-Chinukh (nos. 566-567) says that the laws only apply to males, who fight in the army, implicitly limiting the rules to a military encampment. Rambam explicitly links this law with a military encampment, as implied by the beginning of the passage, “when you go out to encamp against your enemies” (Sefer Ha-Mitzvos, asin 192-193). Sefer Ha-Chinukh adds that this law only applies when the Temple in Jerusalem stands. Based on this, Rav Shaul Yisraeli (20th cen., Israel) argues that the law does not apply today (Eretz Chemdah, p. 65) but he seems to be a lone voice. Similarly, the Rashbatz is a minority voice while the majority of authorities believe that these laws apply only to a military encampment. This raises the question: what is a military encampment?

II. What Constitutes a Military Encampment?

Is one soldier traveling on his own or even a small team considered a camp? In one place, Rambam writes that an encampment requires an eruv (Mishneh Torah, Hilkhos Eruvin 1:3). In another place, he writes that a military encampment is exempt from an eruv (op cit., Hilkhos Melakhim 6:13). Rav Vidal of Tolosa (14th cen.) distinguishes between a military and a civilian encampment. He argues that the Talmud Yerushalmi says that a civilian encampment with ten people requires an eruv. In contrast, the Mishnah exempts specifically a military encampment from eruv (Maggid Mishneh, Hilkhos Eruvin 1:3). According to Rav Vidal, any grouping with fewer than ten people is merely a caravan and not an encampment. The Vilna Gaon (18th cen.) writes similarly (Orach Chaim 158:21, 366:6).

Rav Yeshayah Karelitz (20th cen., Israel) adds that the ten people of an encampment must be in one place (Chazon Ish, Eruvin, Likutim 6:1). Rav Yitzchak Kaufman (cont., Israel), in his classic work on military halakhah, explains that this means they must be enclosed within halakhically valid walls, including appropriate fences or even strings, as stated by Rambam in Hilkhos Melakhim mentioned above (Ha-Tzava Ka-Halakhah: Hilkhos Milchamah Ve-Tzava 10:2).

However, Rav Yitzchak Herzog (20th cen., Israel) disagrees with Rav Vidal’s interpretation of the Yerushalmi as referring to a civilian encampment. Rather, he understands the Yerushalmi as saying that both a military encampment (of ten or more) and a military caravan (of less than ten) are exempt from eruv (Heikhal Yitzchak, Orach Chaim 49:8). Similarly, Rav Shlomo Goren (20th cen., Israel) argues that a military outpost fighting a war, including a long-term ongoing war, constitutes a military encampment even with fewer than ten soldiers (Meshiv Milchamah, vol. 1, p. 158). Therefore, even a small military outpost that is encircled by a halakhically valid wall is exempt from eruv.

III. Do Permanent Bases or Air Force Installations Qualify

Note that the biblical text refers to an encampment going out to war: “When you go out to encamp against your enemies.” What about a permanent military base? Even during wartime, a base of operations is the place from which soldiers leave to go out to war. Some bases are further within the country for training or internal security. Are these types of bases exempt from eruv and do they require enclosed bathrooms or relief areas outside the camp?

Rav Yitzchak Herzog (op cit.) says that a permanent military base where soldiers engage in routine security operations is not considered a military encampment going out to war. Therefore, none of these laws apply. However, Rav Shlomo Goren (op cit., p. 157) argues that soldiers in permanent outposts or border positions, engaged in routine security and patrol, constitute military encampments going out to war to whom these laws apply. Rav Goren (op cit., p. 144) writes that this also applies to soldiers training to go out to war.

What about air force bases? These installations are often located far from combat zones, but they serve as launch points for warfare. Are they halakhically considered military encampments? According to Rav Goren, they clearly qualify. Rav Herzog’s position would leave this question unresolved, as these bases are permanent and distant, but still involve outgoing military action. Rav Kaufman (op cit., 10:7) argues that since soldiers stationed there are actively deployed to war and the base itself is a potential target for enemy fire, then it is halakhically considered a military encampment. An air force base is subject to the Torah’s laws of encampment, including the need for enclosed sanitation facilities.

In our polarized times, many feel justified in mocking anti-Israel protesters whose positions seem morally reprehensible. Yet this impulse raises a fundamental question: do the benefits of attacking our enemies justify the spiritual toxicity of mockery? While some argue that mocking enemies of Israel serves a religious purpose, I believe the halachic sources and practical realities counsel restraint.

I recently expressed these brief thoughts on social media and my good friend, Rav Daniel Z. Feldman, disagreed. (To read Rabbi Feldman’s article, click here.) The Jewish Press asked us both to flesh out our opinions in writing. I am hesitant to disagree with Rav Feldman, a close friend since childhood. He is not only a full week older, but also has always been smarter, more knowledgeable and more pious. I leave for another time my halachic justification for writing this article in the face of his greater expertise, but I add at the end two specific reasons.

The Nature and Danger of Leitzanus

Both the Bible and the Talmud say harsh things about the leitz, the mocker or scoffer. “Judgments are prepared for mockers” (Prov. 19:29), and the Gemara (Avodah Zarah 18b) warns that “anyone who mocks, suffering will befall him.” But what exactly makes mockery so spiritually dangerous?

Mockery is not merely humor, harsh criticism or even a personal insult. It represents a cynical form of denigration that attempts to render its target devoid of value. When we mock, we don’t simply disagree; we dismiss the very possibility that something deserves serious consideration. This attitude corrodes the humility, seriousness and receptivity essential for spiritual life.

As we will see, the Gemara states that mockery is generally forbidden. What prohibition does it violate? Rav Avraham Erlanger offers a profound insight (Birkas Avraham, Sanhedrin 63b)… continued at The Jewish Press

Click here for R. Daniel Z. Feldman’s response

Hospitals, airports and universities often include interfaith chapels which are intended to accommodate individuals of all faiths for individual or group prayer. This religious accommodation raises an important question: May a Jew pray in a room that also houses non-Jewish worship, potentially even avodah zarah (foreign worship, i.e. idolatry or polytheism)?

I. Mushroom Shuls

To answer this, I turn to an episode that occurred in St. Louis in 1951. The quickly growing Young Israel rented a social hall in a local hotel in which to hold their high holiday prayers. The long-standing Beth Medrash HaGadol objected to this larger venue, which would draw many paying members from the larger and more established synagogue, and brought the issue to the attention of Rav Menachem Eichenstein, the Orthodox Chief Rabbi of St. Louis. Rav Eichenstein wrote a responsum forbidding the Young Israel from holding prayers in the rented hall. He sent this responsum to leading authorities who replied with their own responsa, generally agreeing with his conclusion. Among the illustrious respondents were Rav Yonasan Steif, Rav Yosef Eliyahu Henkin and Rav Moshe Feinstein. The exchange of letters takes up the first section of the March 1952 issue of the rabbinic journal Ha-Pardes, and was republished in the 1955 jubilee volume for Rav Eichenstein, titled Berakhah Li-Menachem. Some of the respondents connected this to the problem of “mushroom shuls,” in which groups would rent theaters and ball rooms for high holiday prayers.

An important consideration is the issue of praying in a place where frivolities and even sins take place. Taz (Orach Chaim 154:1) rules that you may not rent a room for prayer if the room above it is unclean. Doing so shows disrespect to the prayer. Rav Eichenstein explains that “unclean” refers to spiritual, as well as physical, uncleanliness. Rav Eichenstein quotes Rav Moshe Schick (Responsa, Orach Chaim, no. 7), who rules that you may not turn an animal pen into a synagogue because it shows disrespect to the mitzvah of prayer. Disrespect of a mitzvah is biblically forbidden, as we see in Shabbos (22a) regarding the biblical commandment to cover the blood of a slaughtered animal. We are not allowed to push dirt over the blood with our feet because that would be disrespectful to the mitzvah.

Rav Moshe Feinstein (in his responsum, later published as Iggeros Moshe, Orach Chaim, vol. 1, no. 31) quotes the Ba’eir Heitev (151:1) in the name of Rav Eliyahu Mizrachi (16th cen., Turkey) as saying that a synagogue does not lose its holiness if someone sins in it (Responsa, no. 81). In that case, a communal functionary had consorted with a young man in the synagogue. Despite the desecration, the synagogue’s holiness remains intact and may continue being used for prayer. Rav Feinstein offers suggestions why that is true but points out that the question assumes that generally we should not pray in a place where sins take place. Rav Yonasan Steif adds that the first verse in Tehillim says: “Blessed is the man… nor sits in the seat of the scornful.” Even when the sinful activity has ended, we may not sit in their seats and certainly not pray there. Since foreign worship is sinful behavior, these authorities would not allow prayer in a room that houses non-Jewish prayer services.

In the responsum mentioned above, Rav Eliyahu Mizrachi rules that a house used for idolatry can also be used for Jewish prayer (quoted in Magen Avraham 154:17). However, Rav Yechezkel Landau (18th cen., Czech) and Rav Moshe Sofer (19th cen., Hungary) disagree and forbid prayer in a house used for idolatry (Dagul Me-Revavah and Chasam Sofer, glosses to Magen Avraham, op cit.). That refers to idolatrous prayer in the past forbidding a place today. Our question is even worse — ongoing foreign prayer. Rav Yosef Eliyahu Henkin (in the book mentioned above, republished in Gevuros Eliyahu 1:24) writes that there is only a possibility to rehabilitate the place if the past improper behaviors are completely ceased and the place no longer is referred to as a house for foreign prayer. But if it is still sometimes used for foreign prayer, it is disrespectful to invoke the divine name in such a place.

II. Interfaith Chapels

In 1950, Cornell University asked Rav Joseph B. Soloveitchik about the propriety of human images in stained glass window in a new interfaith chapel. Rav Soloveitchik replied in the negative and ended with his general opposition to prayer in an interfaith chapel. He writes, “I strongly object to the use of an interfaith chapel. The Halakhah is unequivocally opposed to it and this prohibition is even more strict than that concerning human images… The idea of a common house of prayer is absolutely irreconcilable with the Judaic philosophy of worship” (Community, Covenant and Commitment: Selected Letters and Communications, p. 8).

More recently, R. Dr. Jason Weiner, the Senior Rabbi and Director of the Spiritual Care Department at Cedars-Sinai Hospital, published an article about Cedars-Sinai’s unique interfaith chapel (“Is One Permitted to Daven in the Chapel at Cedars-Sinai?” in Nitzachon: Adas Torah Journal of Torah Ideas, 5:2 Spring 5778). At Cedars-Sinai, a room is designed and designated primarily as a synagogue but is also used for Christian, Muslim and other prayer. The question is whether a synagogue becomes disqualified when it is used also for foreign worship.

R. Weiner received a responsum signed by Rav Zalman Nechemiah Goldberg, Rav Nachum Rabinovitch and Rav Yosef Carmel permitting prayer in such a room because it is built as a synagogue (later published as Be-Mareh Ha-Bazak 8:15). Presumably, they follow Rav Eliyahu Mizrachi and the Magen Avraham, that a synagogue is not invalidated by foreign prayer. R. Weiner showed this responsum to Rav Asher Weiss, who gave his verbal agreement. However, Rav Dovid Feinstein and Rav Hershel Schachter both disagreed and ruled that you may not pray in such a room because it is an interfaith chapel.

It is important to note that the disagreement is only about a room that is primarily a synagogue. The authorities seem to agree that a room designated for all religions is problematic. R. Weiner also quotes Rav Shammai Kehas Gross who forbids praying in an airport interfaith chapel (Shevet Ha-Kehasi 6:83).