Psychology is the science which describes mental states, as physical science describes the behaviour of matter in motion. Both are abstract sciences. Physical science treats nature as the totality of things conceived of as independent of any subject; psychology treats inner experience as independent of any object. Both are outside any idea of value, though it is needless to say that the votaries of both sciences trespass habitually, and often unconsciously. Both are dualisms with one side ignored or suppressed. When psychology meddles with ontological problems--when, for instance it denies the existence of an Absolute, or says that reality cannot be known--it is taking too much upon itself, and has fallen into the same error as the materialism of the last century. On such questions as the immortality of the soul it must remain silent. Faith in human immortality stands or falls with the belief in _absolute values_. The interest of consciousness, as Professor Pringle-Pattison has said in his admirable Gifford Lectures, lies in the ideal values of which it is the bearer, not in its mere existence as a more refined kind of fact. Idealism is most satisfactorily defined as the interpretation of the world according to a scale of value, or, in Plato's phrase, by the Idea of the Good. The highest values in this scale are absolute, eternal, and super-individual, and lower values are assigned their place in virtue of their correspondence to or participation in these absolute values. I agree with Muensterberg that the conditional and subjective values of the pragmatist have no meaning unless we have acknowledged beforehand the independent value of truth. If the proof of the merely individual significance of truth has itself only individual importance, it cannot claim any general meaning. If, on the other hand, it demands to be taken as generally valid, the possibility of a general truth is acknowledged from the start. If this one exception is granted, the whole illusory universe of relativism is overthrown. To deny any thought which is more than relative is to deprive even scepticism itself of the presuppositions on which it rests. The logical sceptic has no _ego_ to doubt with. 'Every doubt of absolute values destroys itself. As thought it contradicts itself; as doubt it denies itself; as belief it despairs of itself.' It is not necessary or desirable to follow Muensterberg in identifying valuation with will. He talks of the will judging; but the will cannot judge. In contemplating existence we use our will to fix our attention, and then try conscientiously to prevent it from influencing the verdict. But this illegitimate use of the word 'will' does not impair the force of the argument for absolute values.