For what it's worth, my personal theory is that the Freudian tradition of psychology (in the broader sense) is not actually a new development but simple a reincarnation of practices that were earlier part of religion, cult, or social rites and interactions. Since modern society would not be able to reconcile these ideas with its self-image, it blanketed what it required under a scientific terminology. This has both been psychology's greatest boon (the scientific method allowed the field to make great strides) and in many cases its most painful problem (have you ever met a dogmatic Freudian with that pathological need to name and lael every last little quirk?).
Thus I would argue that psycholoogy couldn't come into being in its earlier form (much) before it did, but its fubndamental principles - the healing of injured minds - has always been with us.