Segulos and Darchei HaEmori

The Tosefta in Shabbos (Chapters 7 & 8) lists various practices which are prohibited due to the fact that they are darchei haemori. For example, putting thorns in a window to protect a pregnant woman or tying an iron to one's bed. These things all have one basic common feature. They are irrational - meaning they are not scientifically or observably proven remedies. (We will come back to this to try to better define what is considered "irrational".)However, the gemara in Shabbos 67a has a seemingly different rule regarding medicine. Abaye and Rava say that "anything done for healing isn't darchei haemori". The mishna applies this rule to several seemingly irrational medical treatments - tooth of a fox, egg of a grasshopper etc.

How do we reconcile these two sources? Here we will present three rishonim who write on the issue:

Rambam - The Rambam in Moreh Nevuchim 3:37 (see also Rashi in Shabbos there) seems to say that, in fact, when it comes to medicine the rule is the same as any other segulah. If a method of healing is not observable by medical science it is forbidden. He seems to learn that the methods mentioned in the mishna in Shabbos were considered rational healing methods.

Ran - The Ran (Drashos HaRan 12) disputes this approach. He learns that when it comes to healing there are two appropriate methods. There are some healing methods that are physical and there are others that are non-physical. Both are appropriate as long as they effective methods that are shown to work. The only healings that are forbidden are ineffective ones which was the way of the Emori - who used silly useless things to heal.

Rashba - The Rashba (Shu"t 413) writes that the Rambam would agree with this position of the Ran. He compares the non-physical healings of the Ran to a magnet. A magnet has power that cannot be seen - yet of course it works. It is a rational thing to believe that a magnet will draw things to it. So too with non-physical healings. As long as they are established as working, they are perfectly rational and the Rambam would certainly agree that they are permitted.

What seems to be at issue here is really how we define rational. The Rashba seems to be saying that in order for a medicine to be considered rational we don't have to know why it works. We only need to have a rational basis for using the medicine. A rational basis can exist due to logic (it makes logical sense that this medicine should work even though it hasn't yet been tested) or due to observation (we have no idea why it works we just have observed that it does). What is forbidden is to use a medicine that we have no rational reason to believe works. If it makes no sense why it should work, nor has it been observed to work then it is forbidden.

At the end of this discussion it would appear that all three of these rishonim agree that in the mishna in Shabbos there was some rational basis for using those particular methods. Had there been no rational basis it would have been forbidden.

*For a much more in-depth discussion on this issue see RJJ Journal Vol. 54 - Segulot, Superstitions, and Darchei Emori by Rabbi Yitzchok Gutterman.