What do some ancient Greek ideas about the mind and reality (such as, for example, Thales, Heraclitus, Parmenides, Pythagoras, Plato) imply about psychology today?

text:  B. R. Hergenhahn & Tracy Henley, An Introduction to the History of Psychology, 2019.  7th ed. Thomson/Wadsworth. ISBN-10: 1133958095  |  ISBN-13: 9781133958093