Let me then without further preamble embark upon that somewhat detailed survey of human faculty, as manifested during various phases of human personality, which is needful in order to throw fresh light on these unfamiliar themes. My discussion, I may say at once, will avoid metaphysics as carefully as it will avoid theology. I avoid theology, as already explained, because I consider that in arguments founded upon experiment and observation I have no right to appeal for support to traditional or subjective considerations, however important. For somewhat similar reasons I do not desire to introduce the idea of personality with any historical _résumé_ of the philosophical opinions which have been held by various thinkers in the past, nor myself to speculate on matters lying beyond the possible field of objective proof. I shall merely for the sake of clearness begin by the briefest possible statement of two views of human personality which cannot be ignored, namely, the old-fashioned or common-sense view thereof, which is still held by the mass of mankind, and the newer view of experimental psychology, bringing out that composite or "colonial" character which on a close examination every personality of men or animals is seen to wear. The following passage, taken from a work once of much note, Reid's "Essay on the Intellectual Powers of Man," expresses the simple _primâ facie_ view with care and precision, yet with no marked impress of any one philosophical school: The conviction which every man has of his identity, as far back as his memory reaches, needs no aid of philosophy to strengthen it; and no philosophy can weaken it without first producing some degree of insanity.... My personal identity, therefore, implies the continued existence of that indivisible thing which I call myself. Whatever this self may be, it is something which thinks, and deliberates, and resolves, and acts, and suffers. I am not thought, I am not action, I am not feeling; I am something that thinks, and acts, and suffers. My thoughts and actions and feelings change every moment; they have no continued, but a successive existence; but that _self_ or _I_, to which they belong, is permanent, and has the same relation to all succeeding thoughts, actions, and feelings which I call mine.... The identity of a person is a perfect identity; wherever it is real it admits of no degrees; and it is impossible that a person should be in part the same and in part different, because a person is a _monad_, and is not divisible into parts. Identity, when applied to persons, has no ambiguity, and admits not of degrees, or of more and less. It is the foundation of all rights and obligations, and of all accountableness; and the notion of it is fixed and precise. Contrast with this the passage with which M. Ribot concludes his essay on "Les Maladies de la Personnalité."