eliminating negatives: qualitative vs. quantitative approaches

The Toras Kohanim presents a dispute between R’ Yehudah and R’ Shimon on how to understand the blessing of ‘v’hishbati chaya ra’ah min ha’aretz” which appears at the end of Sefer vaYikra. R’ Yehudah interprets the bracha to mean that there will no longer be wild animals, but R’ Shimon disagrees and interprets the pasuk to mean that wild animals will still exist, but will behave tamely, in the classic fashion of the lion lying down with the lamb.

It takes the creativity and genius of the Rogatchover to see the connection between this dispute and the issue we raised yesterday with respect to whether bitul chameitz means a qualitative or quantitative destruction. “Hishbati chaya…” shares the same root as “tashbisu chameitz”. R’ Yehudah who interprets that bitul chameitz must be done by burning, eliminating the quantity of chameitz from existence, also holds that “v’hisbati chaya” means that wild animals will cease entirely to exist. The opposing view holds that “hishbati” need not mean elimination of a quantity, but can also mean a qualitative change. Wild animals which no longer act wild also counts as a fulfillment of the bracha. In that same vein, if one took a bot of chameitz and mixed it with matzah so it became bateil before Pesach, although the same quantity of chameitz still exists, the fact that the mixture halachically is not considered to have the quality of chameitz fulfills the mitzvah of tashbisu.

Moving out of the world of lomdus, perhaps there is an issue of mussar here as well. What is the best approach to vanquish the “chaya ra’ah” within? Should one aim for complete elimination of negative tendencies, or perhaps those tendencies can be sublimated toward a higher good and in that way eliminate the negative consequences?