It is not my business to make known matters that would only stir controversy about past history quite uselessly. But it would be a serious omission of duty not to utter a warning that human perfection does not exist; that famous figures in history, politics, warfare, government, literature, religion, mysticism, and art have committed grave errors of judgement, impression, or teaching; that these errors are known only to a few in each case, and will probably never be known to posterity at all. A man may be successful in leading his people through a war to final victory but, on the way, he may have made blunders that were heavily paid for by others. A teacher may be spiritually enlightened but personally inexperienced; his opinions on unfamiliar matters may not have much value.
-- Notebooks Category 1: Overview of the Quest > Chapter 6: Student-Teacher > # 278