I have found little that is good about human beings on the whole. In my experience most of them are trash, no matter whether they publicly subscribe to this or that ethical doctrine or to none at all. That is something that you cannot say aloud, or perhaps even think.

Summary

This quote suggests that the speaker has a pessimistic outlook on humanity, expressing disappointment in their interactions and beliefs. They believe that many individuals are morally corrupt, regardless of their professed ethical principles. However, the speaker acknowledges the taboo nature of openly voicing such thoughts, highlighting the unspoken nature of this judgment. It implies that this negative perception of people is best kept to oneself, as it may not be socially acceptable to express such sentiments.