Letter 30 is superb and it’s definitive in Mussar circles, yet it’s quite long, so we’ll present it in parts in order to give the entire letter its due.
R’ Salanter begins with the insight that while there are some people who are inherently sensitive, giving, and good and others who are the opposite, it’s also true that each one of us is often a conflicted combination of the two. So, what are we to do to be the truly good people we sometimes are and are capable of being from now on? We’re to start off by avoiding saying that we can never change. “That’s simply not true,” R’ Salanter asserts, “for the forces in one’s soul”, i.e., our inner drives and traits, “can truly be mastered and transformed”. He proves this quite astoundingly with the simple fact that since we can change our pets’ behavior by training them, then we ourselves can certainly be “trained” and changed for the better too, through study and force of habit!
Indeed, we’re all enjoined to improve ourselves, given that “the whole point of our existence is to purge ourselves of negative traits” he avows (and how stunning a statement that is!). After all, weren’t our forefathers great and noble people, and haven’t we each been bidden to say longingly, “Oh when will my deeds reach the level of my forefathers?” (Tanna D’Bei Eliyahu 25).
It’s also true, he adds, that the whole point of the creation of the universe was to bring about “a perfect individual” — one who “fears G-d and observes His commandments” as best as is humanly possible (which is another stunning statement!). R’ Salanter makes the point that “everyone has it within him to rectify all the forces in his physical being” that would prevent his bettering himself.
There’s one more thing we must do, though. For, not only must we always try to better ourselves trait by trait but we must also conquer the yetzer harah itself, the source of all of our vices. So, we must each determine the traits that throw us off and work hard enough on expunging them from us that they became anathema to us — distasteful rather than longed for, an enemy rather than an ally. R’ Salanter then adds that most of this touches on traits that are relevant to our interactions with other people rather than to our relationship to G-d Himself and His ceremonial requirements, as we’ll see below.
R’ Salanter cites Rambam’s great Mussar work, “The Eight Chapters” (Ch. 6) to illustrate his contention. Rambam discusses the fact that there are two sorts of righteous people: one type that does all they can to avoid sin despite their personal desires and conflicts, and the type that simply isn’t drawn to sins and thus quite naturally avoids them.
Which is more admirable? As Rambam explains, it depends on the type of sin in question. We should all inherently abhor robbery (which is an interpersonal transgression), for example, and could easily be “righteous” when it comes to it, while most of us wouldn’t always find it easy to fast on Yom Kippur (which is a ceremonial transgression), and find it hard to be righteous in that realm. Thus it’s clearly easy enough to avoid theft and the like, and one can’t take a lot of credit for that, R’ Salanter indicates. Yet his implication is that it’s also difficult to have compassion on others, to go out of your way to do them favors, and the like — which are also interpersonal mitzvahs. Doing the latter well and often is thus even more admirable than being sure not to steal from someone, etc. (Though we’re also required to be righteous when it comes to ceremonial mitzvahs.)