Q&A: Two Kinds of Occam’s Razors
Two Kinds of Occam’s Razors
Question
Hello Rabbi Michi,
If I encounter several cases that could all be explained by one single explanation, or alternatively by a separate explanation for each case, then according to the razor I should choose the explanation that can account for all of them. So far, that is simple and clear. But what happens when the individual explanations already exist? I’ll give an example:
Tosefta Bava Kamma chapter 10 has several cases regarding acquisition of stolen property through a change that do not fit with the Talmud in chapter 9.
Talmud: If slaves aged or produce spoiled, he pays according to the value at the time of the theft.
Tosefta: If slaves aged or produce spoiled, he says to him, "Here is what is yours before you."
To explain the Tosefta, one can use the existing answers in the Talmud: that regarding slaves it follows the view of Rabbi Meir, and regarding produce it is dealing with a case where they did not spoil very much. But one could also offer a single answer saying that unlike the Talmud, the Tosefta puts the emphasis on whether the person actively made a change in the object (this reasoning is reinforced by the Tosefta’s words: "This is the general rule: any stolen item that remains as it is, and he did not change it from its original state, he may say to him, 'Here is what is yours before you.'"). But for this explanation we would need to ‘innovate’ something new.
So if we are looking only at the considerations of the razor, would it be better to give existing but separate explanations for each case, or a new explanation that can account for everything? Even if you do not agree with the specific example I brought here, I would still be happy to hear an answer to the general question.
Answer
The razor principle has received quite a bit of criticism. For example, some argue that the razor principle leads to unjustified conservatism. What seems simple to me is always whatever I currently think, and so the razor principle would tell me simply to remain with my present position. The assumption here is that simplicity is not a fully defined matter (and not an objective one). Beyond that, the razor principle compares explanations of equal force, and among them one should choose the simpler one. But it is not clear when explanations really are of equal force, or whether there is an objective measure for that. Thus, for example, one might propose adopting Newtonian mechanics because it is simpler than quantum mechanics or relativity. But that is nonsense, of course, because the two newer theories explain more facts and are more valid, and therefore they should be adopted even though they are much less simple.
In our case, there is no clear criterion for using the razor principle, and so one must be careful about following it when the situation is not unequivocal. If in your opinion your explanation is more correct and better fits the language of the Tosefta, there is no reason to give it up because of the razor principle. And even if the individual explanations already exist (that is, they explain other facts that are not presently under discussion), it is possible, and perhaps preferable, to adopt them as well, even if the razor principle would seemingly rule that out.
In short, the razor principle says: take what is most plausible. But what is most plausible depends on you. In most cases this principle does not add much. Only when there is a clear comparison might the situation be different (originally Occam spoke about how many entities the explanation assumes, which is a clear and objective quantitative comparison, though even there the above points are open to discussion).