The Stoics and Socrates The question of the reality of the soul and its distinction from the body is among the most important problems of philosophy, for with it is bound up the doctrine of a future life. The soul may be defined as the ultimate internal principle by which we think, feel, and will, and by which our bodies are animated. The term "mind" usually denotes this principle as the subject of our conscious states, while "soul" denotes the source of our vegetative activities as well. If there is life after death, the agent of our vital activities must be capable of an existence separate from the body. The belief in an active principle in some sense distinct from the