By the Grace of G‑d
22 Elul, 5721 [September 3, 1961]
Brooklyn, N.Y.

Greeting and Blessing:

The Torah, our guide to life, tells us that regarding all matters "[G‑d] has set before you life and good, and death and evil" with the hope that, as the verse concludes, "you shall choose life"...

But the evil inclination often garbs itself in nice and virtuous garments, enticing the person with arguments that on the surface seem righteous and just. How then-goes the famous question-might a person know if a certain argument has been put forth by the good drives in the heart or by the evil ones?

One way is to examine your long-term feelings about what you have done. When a person is driven to do an evil act by a surge of lust and desire, he inevitably has feelings of regret afterwards; indeed, the more time goes by (taking him further away from the temporal rewards of his evil deed), the stronger these feelings grow. On the other hand, with a good deed, a person only becomes more and more satisfied over time with the choice he made...

(Free translation of an excerpt from a letter)