In order to succeed at Mussar study, R’ Salanter offers, one would need to know “the ways of the world”. This is a very important term in R’ Salanter’s system so it’s vitally important for us to understand it.
Rather than referring to how the world itself functions — on a biological or chemical level, or on a political or societal level, and the like as we might expect from the term — R’ Salanter is referring to something else. He takes knowing “the ways of the world” later on in this letter to refer to knowing how people really act, rather than how they appear to. Thus, it’s knowing the ways we interact with each other (and ourselves) and how each really feels.
He’s thereby making the point that one would need to truly know his own heart and the heart of others if he’s to grow in his being and to help others grow, too. After all, how could anyone hope to be the best he can be without that? And one only comes to that through Mussar study and deep, honest introspection.
R’ Salanter then makes the point that since we’ll all need to account for our lives some day, and that we’d thus do well to make the right decisions as we go along, we’d obviously need to know just where we go off, and how we manage to fall for the sorts of things that “cast their (insidious) influence over our thoughts, and seep down to the very core” and influence us negatively. And the best tool for that is the acquisition of true Fear of Heaven.
For, it inspires us to examine our ways and intentions, and it enables us to get to the point where “the chaff is separated” from the wheat of our hearts, and it’s “driven away by the wind” of our new understanding. The Fear of Heaven also gives us the strength to fight the untoward tendencies that “confuse us, and dance within us” so ominously.
But we’d need to be honest with ourselves if we’re to succeed at all that — “to set the truth before our eyes” and dwell on it, and to keep a frank and honest eye on our actions, so as to stop “bungling about in the dark”. Knowing “the ways of the world” clearly helps in all that.
With it, we’d catch sight of our gluttonies, our lust for honor, and all other such failings. And it would also remind us that — like any astute business person would know — we need to plan for the future and take everything into account if we’re to succeed.
Such knowledge would also help us “grow wise in the ways of our souls” and would then “lighten our burden”, giving us the information we’d need to grow, and to be hesitant about sinning. At bottom, then, knowing our true inclinations and fostering a healthy dose of the Fear of Heaven will enable us to cleanse our hearts. But we’re to never forget that all of that only comes about through regular Mussar study, which we’re to encourage in others as well as ourselves.