reach the ultimate and primary truths, which are the sources of all our knowledge, and which cannot be denied or doubted without denying or doubting the evidence of Consciousness itself—­that is, the only evidence that there is for anything.  I maintain this to be a misconception of the condition imposed on inquirers by the difficulties of psychological investigation.  To begin the inquiry at the point where M. Cousin takes it up is, in fact, to beg the question.  For he must be aware, if not of the fact, at least of the belief of his opponents, that the laws of the mind—­the Laws of Association, according to one class of thinkers, the Categories of the Understanding, according to another—­are capable of creating, out of those data of Consciousness which are uncontested, purely mental conceptions, which become so identified in thought with all our states of Consciousness, that we seem, and cannot but seem, to receive them by direct intuition.  For example, the belief in matter in the opinion of these thinkers is, or at least may be, thus produced:—­

’"The proof that any of the alleged Universal Beliefs, or Principles of Common Sense, are affirmations of Consciousness—­supposes two things:  that the beliefs exist, and that they cannot possibly have been acquired.  The first is, in most cases, undisputed; but the second is a subject of inquiry which often taxes the utmost resources of psychologists.  Locke was therefore right in believing that ‘the origin of our ideas’ is the main stress of the problem of mental science, and the subject which must be first considered in forming the theory of the Mind."’

This citation from Mr Mill’s book is already almost too long, yet we could have wished to prolong it still more, from the importance of some of the succeeding paragraphs.  It presents, in clear discrimination and contrast, two opposite points of view according to which the phenomena of mind are regarded by different philosophers, and the method of studying them determined:  the introspective method, adopted by M. Cousin and others—­the psychological or analytical method, pursued by Locke and by many other eminent men since Locke—­’the known and approved method of physical science, adapted to the necessities of psychology’—­(p. 148).

There are passages of Sir W. Hamilton’s writings in which he appears to feel that the introspective method alone is insufficient for the interpretation of Consciousness, and that the analytical method must be employed to reinforce it.  But on this as on other points he is not always consistent with himself.  For in laying down the principle upon which the primary truths of Consciousness, the original data of intelligence, are to be ascertained and distinguished from generalizations out of experience and custom, he declares that the one single and certain mark is Necessity—­they must be beliefs which we are under the necessity of believing—­of which we cannot get rid by