Both philosophy and psychology are intent on explaining aspects of our observable world, with psychology limited to explaining human behavior, while philosophy relates human behavior to a much broader interest in, literally, everything. At some level, of course, philosophy is also a science of the human mind, for like psychology it tries to explain the workings of the mind, the relationship between the mind and the external world, and how the mind can know anything at all about either itself or the outside world. Psychology itself, like science, is a form of philosophical inquiry that has served as a primary paradigm of human behavior in the modern age. A more recent philosophical paradigm, existentialism, developed in reaction to psychological insights and to the prevalence of the scientific method as the primary means to truth in this century.
A number of new ideas emerged during the period after 1880, ideas that had their genesis in earlier philosophical movements and that now emerged under the scientific approach that changed the emphasis from isolated thought to experimentation. The basic shift was not from awareness to uncertainty but from reliance on tradition to reliance on science and psychology for explanations and guidelines. Yet, it is also true that this produced a great deal of uncertainty simply because the scientific approach always holds out the possibility of being wrong, something that tradition does not. The scientific methods yields knowledge that is accepted until it is challenged by new evidence, and even as the general public may accept science as being real and true on its face, underlying that is a feeling of immanent change.
The emergence of psychology as a discipline, however, did throw doubt on our thought processes and behaviors, for underlying Freudian theory as the idea that our behavior derives from forces of which we are not conscious and over which we normally have no direct control. ...