The Rambam on the Linearity of Time, or Its Lack of Thereof.

The קובץ הערות in the הוספות to :יבמות דף סא (found in the back of the שו״ת הרשב״א), brings the רמב״ם פ׳ ט״ו מהל׳ אישות ה״ב which says that “If someone is busy with learning תורה, he is פטור from his חיוב to marry; in order so that he won’t have to be busy with providing for his family, and thus be מבטל תורה, he can push off his obligation, שהעוסק במצוה פטור מהמצוה, and for sure if that מצוה is תלמוד תורה.”

But the גמ׳ in :מועד קטן דף ט says that this that one can be מבטל a מצוה in order to learn תורה, only applies in a case where the מצוה can be accomplished by someone else. If so, how can the רמב״ם say that if one is learning תורה then they don’t have to get married, if this is a מצוה that no one else can accomplish? The גמ׳ is משמע that we only apply the rule of עוסק מצוה פטור מהמצוה where someone else can still do the מצוה!

Answers ר׳ אלחנן, that from this that the רמב״ם uses language of “pushing off”, rather than “completely פטור”, we see that he holds that a מצוה that you can do yourself at a later time is considered a מצוה that “someone else” can accomplish, and you can therefore push it off until later for the purpose of learning תורה. Since it’s considered that your future self is considered “another person” the parameters in מועד קטן for when we can say עוסק במצוה פטור מהמצוה are fulfilled.

Now. How can we say that one’s future self can be considered as “another person”? According the the standard linear understanding of time, since we constantly progress along time, with each moment in the future coming into being as we collectively experience it, and each moment in the past disappearing forever, one’s future self would not be able to be considered “another person” at all! It is simply ourselves at a later time! Since the future does not exist until experienced, our future selves too, do not come into being until the moment in which they exist, and therefore, at the moment at which one is learning, no future self exists to perform the מצוה.

Thus, in order to make sense of this רמב״ם the only possible explanation is that in fact, time is not linear at all. Rather, all moments of time are happening simultaneously. That is to say, in every moment, every moment that has ever existed in the past, as well as every moment that will ever exist in the future are all happening together with the present at different points on the space-time continuum. Now the רמב״ם makes sense. Since your future self does in fact exist at the same time as your present self, it can now be considered as though there is indeed “another person” to whom you can push off the מצוה to, because he exists at the same time that you do.

The point I’m trying to make, Ma, is that yes; I do in fact believe that “someone else” will clean up my room after me. I wasn’t trying to be chutzpadik. Can I please have dinner now?