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. Various theories as to the nature of the soul have claimed to be reconcilable with the belief of immortality, but it is a sure instinct that leads us to suspect every attack on the actuality or spirituality of the soul as an assault on the belief in existence after death. The soul may be defined as the ultimate internal principle by which we think, feel, will, and essence of the human body. 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. That our vital activities proceed from a principle capable of subsisting in itself, is the thesis of the substantiality of the soul: that this principle is not itself composite, extended, corporeal, or essentially and intrinsically dependent on the body, is the doctrine of spirituality. If there be a life after death, clearly the agent or subject of our vital activities must be capable of an existence separate from the body. Even uncivilized peoples arrive at the concept of the soul almost without reflection, certainly without any severe mental effort. The mysteries of birth and death, the lapse of conscious life during sleep and in swooning, even the commonest operations of imagination and memory, which abstract a man from his bodily presence even while awake-all such facts invincibly suggest the existence of something besides the visible organism, internal to it, but to a large extent independent of it, and leading a life of its own. In the rude psychology of the primitive nations, the soul is often represented as actually migrating to and fro during dreams and trances, and after death haunting the neighbourhood of its body. Nearly always it is figured as something extremely volatile, a perfume or a breath. Often, ...