Morris Ayin is missing.

Morris was a big influence in the old days. He often determined what was proper and what was not. When I was 5, for example, my father refused to allow pareve margarine on the table during a meat meal "because of Morris Ayin." I never met Morris myself, but I was impressed nonetheless that he commanded such authority in our home.

Near the end of fourth grade, when we were rounding the far turn on a lightning exploration of the Babylonian Talmud tractate Bava Metzia (fourth-graders do not often get into hot and heavy debating of Talmud passages), I discovered who Morris really was. He was not a person, at all, but a principle of Jewish law (moris ha’ayin, or marit ha’ayin in modern Hebrew pronunciation) that in translation means "for the sake of appearances."

The issue in that case was whether it was permitted to muzzle an ox that was trampling on Temple-designated grain in order to remove its husks. Muzzling an ox is prohibited by Torah law (Deuteronomy ‘5:4), but what if the grain being trampled on no longer belongs to the ox’s owner? How could he allow his ox to eat what does not belong to him?

BT Bava Metzia 89b-90a solves the problem. The animal should be muzzled, "but because of marit ha’ayin, he brings a lump of that species and hangs it from the [feed] basket on its mouth." That way, to someone walking along the road who does not know that the ox and the grain had different owners, it will appear as though the owner is not violating a halachic precept after all.

My otherwise glazed-over eyes lit up. It was not over the notion of an ox stomping on grain, which is a concept way beyond the capacity of a fourth-grader on the Lower East Side who had never seen an ox or unhusked grain up close and personal. No, my eyes lit up because I finally understood why we could not put pareve margarine on a fleishig table — because we did not want to give anyone walking by our window the wrong idea, that we were mixing meat with "milk."

The problem, of course, was that our window was on the fifth floor of an apartment building on the corner of Clinton and Grand streets, so anybody walking by it was more likely to give us the wrong idea. When I asked my father about whether what really worried him was that Superman was out there playing peeping Tom, he gave me the definitive answer for everything that did not make sense: "That is the way it’s written." (It sounds better and more authoritative in Yiddish.)

As I learned several years later, however, this time the answer was on the money. In BT Shabbat 64b and several other places in the Talmud it states: "Rav Yehudah said in Rav’s name: In every instance in which the Sages prohibited [something] for marit ha’ayin, [the thing] is forbidden even in the inner rooms." In other words, it was prohibited even if no outsider was likely to see it.

To be sure, not everyone agreed with this principle all the time, especially those two classic halachic sparring partners, Beit Hillel and Beit Shammai (see BT Beitzah 9a-b), but all did agree on the principle as a general rule.

Perhaps its most relevant examples are found in BT Avodah Zarah 1’a. Three situations are presented. In one, a person gets a splinter in his foot while walking by an idol. In the second, a man drops some loose change in front of the idol. In the third, there is a spring of fresh water, from which a man might want to drink, immediately in front of the idol. In all three cases, the man would have to bend down, and this could appear to someone else to be him bowing down to the idol. Unless he can bend down in a way that makes it clear that he is not bowing down to the idol, he may not bend down until he is out of its presence.

The Talmud then wonders why the three cases were necessary, when one would have sufficed. Not so, comes the answer. If just the splinter case was mentioned, we may assume he could not bend down because he could walk a few feet away and then deal with the offending sliver. So we are given the case of the coins, which could be retrieved nowhere else but in front of the idol. Now, however, it could be argued that the prohibition attends because it was only money. So the case of the water is given. It could be argued that someone who is dying of thirst would be permitted to bend down and get a drink, but he may not do so nonetheless.

This brings us back to Pesach. If a person dying of thirst may not bend down before an idol to drink from a pool of refreshingly fresh water, why is it permissible to have "macaroni and cheese" on Pesach, or "Cheerios," or "bagels," merely because these are not the real thing?

The purpose of such foods, of course, is to make Pesach more "fun" for children and more "palatable" to adults. In the process, however, we lose something far more important. The food, after all, is incidental. Pesach itself is unique; the food restrictions and other distinctive features that accompany it are designed to emphasize that uniqueness. We wipe that out when the only difference between yesterday and today is that the bagel is not as chewy and the Cheerios taste a bit funny.

Aesthetics aside, however, it was hard enough "in the old days" to make a convincing case for many of the Pesach food restrictions. It becomes even more difficult when "substitute" foods appear with appropriate certification and the justification is that the product is merely faux chametz.

Where, oh where, has Morris gone?