There are two types of men in this world… What are they?

A renowned psychologist, Viktor Frankl - Wikipedia was the founder of Logotherapy - Wikipedia, a theory of psychology that holds that a person's primary motivation is to find meaning in life.

Frankl developed his theory during his years in a series of Nazi concentration camps. In his acclaimed memoir of this period, Man's Search for Meaning - Wikipedia, Frankl pretty much settled the question about the two types of men, two types of humans really, decent and indecent (see below from Man's Search for Meaning. Viktor E. Frankl, 1946, emphasis mine). ‘Pretty much settled’ because life experience in general seems to bear out the essential truth as Frankl perceived it, albeit most of the rest of us are much more fortunate and never experience such hellish, exigent circumstances.

Human kindness can be found in all groups, even those which as a whole it would be easy to condemn. The boundaries between groups overlapped and we must not try to simplify matters by saying that these men were angels and those were devils. Certainly, it was a considerable achievement for a guard or foreman to be kind to the prisoners in spite of all the camp's influences, and, on the other hand, the baseness of a prisoner who treated his own companions badly was exceptionally contemptible. Obviously the prisoners found the lack of character in such men especially upsetting, while they were profoundly moved by the smallest kindness received from any of the guards. I remember how one day a foreman secretly gave me a piece of bread which I knew he must have saved from his breakfast ration. It was far more than the small piece of bread which moved me to tears at that time. It was the human "something" which this man also gave to me - the word and look which accompanied the gift.

From all this we may learn that there are two races of men in this world, but only these two - the "race" of the decent man and the "race" of the indecent man. Both are found everywhere; they penetrate into all groups of society. No group consists entirely of decent or indecent people.

https://www.quora.com/There-are-two-types-of-men-in-this-world-What-are-they/answer/Tirumalai-Kamala