This identification runs counter to a number of very common and very dear delusions: we constantly imagine that the difference between ourselves and a great painter or a great poet does not consist in the power of seeing and feeling, but in a supposed gift of merely external expression; and again, we credit ourselves with a number of thoughts and images, which we might express if we only wished to. The easiest way to free ourselves of such delusions is to try to express whatever it seems to us that we possess: it becomes then apparent that our pictorial or poetical intuitions are really mere fragments, or echoes, of intuitions; are, in fact, not more than that which we succeed in expressing. It must however be borne in mind that we give here to the word expression a purely mental or spiritual significance: we mean by it the image that we form in our mind, and of which the painting or the poem, as objects, are the material extrinsications. It requires but little reflection to realize that there is no painting or poem--there is no word that we utter--unless it be a mere _flatus vocis_, which has not been preceded in our mind by an internal image, which is the true expression. The reader will have remarked that, in order to give examples of intuitive knowledge, we have now had recourse to poetry and to painting. The fact is that there is no difference between intuitive knowledge, or expression, and art, except a purely extensive and empirical one: that is, we call a poet or an artist a man who possesses this expressive power in a higher degree than the rest of mankind; we call a poem or a work of art an expression which is fuller, more complex, more elaborate, than those which are the product of our common intuitive activity, mere waves of the continuous stream of spiritual life, in which they are constantly interrupted by and mixed with reflections and volitions, with logical and practical facts. The difference between the genius and the common man, in the æsthetic as well as in the other spheres of human activity, is a quantitative, not a qualitative one. Art is not a peculiar spiritual function, and therefore a closed circle to which none but the elect are admitted: the artist appeals to the intuitive man in each of us, in a language of which every human mind finds the key within itself.