In order to grasp reality we must use the faculty of contact or immediate feeling, or, as Bergson calls it, intuition. Intuition is a different order of knowledge, it is moulded on the very form of life, and it enables us to enter into life, to be one with it, to live it. It is "a direction of movement: and, although capable of infinite development, is simplicity itself." This is the mystic art, which in its early stages is a direction of movement, an alteration of the quality and intensity of the self. So Bergson, making use of and applying the whole range of modern psychology and biology, tells us that we must develop intuition as a philosophical instrument if we are to gain any knowledge of things in themselves; and he is thus re-echoing in modern terms what was long ago stated by Plotinus when he said-- Knowledge has three degrees--opinion, science, illumination. The means or instrument of the first is sense, of the second dialectic, of the third intuition. To the last I subordinate reason. It is absolute knowledge founded on the identity of the mind knowing with the object known. (_Letter to Flaccus._) We have discovered that sense knowledge, however acute, has to be corrected by the intellect, which tells us that the sun does not go round the earth, although it appears to our observation to do this. So possibly, in turn, the intellect, however acute, may have to be corrected by intuition, and the impotence of brain knowledge in dealing with the problem of life is leading slowly to the perception that to _know_ in its true sense is not an intellectual process at all.