Rav Nosson Zvi Finkel, the Alter of Slabodka


He use to say that a person should always suspect himself, for even his good deeds may stem from impure motives.  “Perhaps,” he said, “the reason I built my whole Mussar approach on the greatness of the first man stems from the fact that the first shmuse I heard from R’ Simcha Zissel Ziv was on that subject.”


From Sparks of Mussar by R Chaim Ephraim Zaitchik