R’ Salanter discusses the magisterial mitzvah of Torah study here and he breaks it down to its two major aspects: study per se, and expertise.
(The truth is that R’ Salanter’s mastery of the material cited and analyzed as well as his original treatment of it cannot be expressed here since all of that is beyond our purview. The reader would do well to delve into the original to catch sight of that and to witness his original genius.)
He points out that one could delve into very many areas of Torah to live up to the injunction to simply study Torah including Mishna, Talmud, Midrash, Mussar, and more. Some of those areas of study are quite practical while others are completely theoretical; some call for deep contemplation and others need to be ruminated upon from time to time until they have an effect; some affect one’s inner core and others explain a number of things that are satisfying to discover, and the like. But the point is that they are all part of the mitzvah of Torah study.
But to be said to have true expertise in Torah study, R’ Salanter offers, one would have to have mastered the Talmud, the very many halachic codes, as well as the writings of the halachic decisors (poskim, in Hebrew) — even if one weren’t striving to be a rabbi or a halachic decisor himself. Because at bottom Torah expertise comes down to determining just what it is that G-d Almighty wants us to do in this world to serve Him and to be the best Jews and people we can be. That sort of Torah study is a life-long process and it’s all-encompassing, and it requires great mental acuity and dedication.
(Other great rabbis and teachers would offer that we could and perhaps even should have expertise in other realms of Torah to have true expertise in it, but while that’s important to know it’s nonetheless beside the point for our purposes here.)
But R’ Salanter then makes the stark and clear-cut point that Torah expertise also requires a high degree of Yiras Shamayim — “fear of Heaven”. (What that comes to at bottom is a high awareness of G-d’s presence in one’s life, a deep desire to please Him each and every way one can, and a true fear of not achieving that.)
He says that “it’s vitally important that one’s scholarship be permeated in Yiras Shamayim, for without it, one’s wisdom can be a source of corruption and serve as a stumbling block for sin!” For without it, one makes halachic decisions that are based on one’s own “vested interests and personal proclivities (which) corrupt one’s intellect”.
And he underscores the fact that acting out of one’s vested interests and the like is “a grievous sin” because “the Torah is not man’s that he can do with it as he’d like — it belongs to G-d alone”, and one may not “fabricate a ‘new Torah’ from his own mind”.