We’ve been exploring situations in which we have a presumption about the status of a person (e.g., that they are married) or an object (e.g., that is it ritually pure) but lack evidence to be certain. As part of the discussion, the Gemara cites Mishnah Tahorot 3:8.
If a child is found alongside ritually pure started dough with risen dough in their hand, Rabbi Meir deems the started dough pure, and the rabbis deem it impure, because it is the manner of a child to handle items.
A pile of dough is (or was) ritually pure and a nearby child has some dough in their hands. The rabbis declare the pile of dough impure on the assumption that the child rendered it so while grabbing a handful (the hands of young children are considered to be ritually impure because they are naturally grabby and not developmentally able to maintain the purity of their hands). But this is not certain. (After all, a parent might have given the child some dough to play with, precisely to keep them from messing with the pure dough.) Rabbi Meir disagrees with his colleagues, declaring the suspicious dough ritually pure, but does not provide a reason, so the Gemara continues:
What is the reasoning of Rabbi Meir? He holds that a majority of children handle items and a minority do not handle items, and the dough itself retains a presumptive status of purity. And if one appends the minority of children who do not handle items within reach to the presumptive status of purity of the dough, the force of the majority of children who handle items within reach is weakened.
True, says Rabbi Meir, young children like to touch things — but not all young children. Since we do not have proof that the dough in the child’s hands was taken from the pure pile on the table, we can’t be certain that the child caused the dough to be impure. Lacking certainty, the pile on the table, which was presumed to be pure, maintains its presumed status.
And the rabbis contend that the minority is considered like it does not exist.
Yes, say the rabbis, we are not certain that this particular child touched the pile of dough, but we can’t ignore the fact that most children are likely to have done so. And so, they argue, the presumed status of the dough is overridden. The likelihood that the child touched it is enough to render the dough impure.
Note that the rabbis and Rabbi Meir do not disagree about how young children behave; both assume that the majority of young children will act on their curiosity and grab some dough from a pile on the table. They also agree that a few children will refrain from handling the available dough. Where they disagree is about how these assumptions affect the law, and in this case, the status of the dough on the table.
Rabbi Meir maintains that the presumptive status holds until we are certain that the dough had become impure. Why assume the worst? Since it’s possible that the dough is pure, let’s assume that is it, until we have evidence to the contrary. The rabbis, on the other hand, set aside the possible and rule based on the probable. Since it is more likely that the dough on the table has been contaminated, we should treat it as if it was. When in doubt, follow the odds.
Read all of Kiddushin 80 on Sefaria.