The free play of the faculty of cognition which had been determined by Kant is also developed by Schiller. His representation of this matter is this: Man, as a spirit, is reason and will, self-active, determining, form-giving; this is described by Schiller as the form-instinct; man, as a sensuous being, is determinable, receptive, termed to matter; Schiller describes this as the material instinct, "Stofftrieb." In the midst between these two is situated the beautiful, in which reason and the sensuous penetrate each other, and their enjoyable product is designated by Schiller the play instinct. This expression is not happily chosen. Schiller means to describe by it the free play of the forces, activity according to nature, which is at once a joy and a happiness; he reminds us of the life of Olympus, and adds: "Man is only quite a man when he plays." Personality is that which lasts, the state of feeling is the changeable in man; he is the fixed unity remaining eternally himself in the floods of change. Man in contact with the world is to take it up in himself, but to unite with it the highest freedom and independence, and, instead of being lost in the world, to subject it to his reason. It is only by his being independent that there is reality out of him; only by being susceptible of feeling that there is reality in him. The object of sensuous instinct is life; that of the purer instinct figure; living figure or beauty is the object of the play instinct. Only inasmuch as life is formed in the understanding and form in feeling does life win a form and form win life, and only thus does beauty arise. By beauty the sensuous man is led up to reason, the one-sided tension of special force is strung to harmony, and man made a complete whole. Schiller adds that beauty knits together thought and feeling; the fullest unity of spirit and matter. Its freedom is not lack, but harmony, of laws; its conditions are not exclusions, inclusion of all infinity determined in itself. A true work of art generates lofty serenity and freedom of mind. Thus the aesthetic disposition bestows on us the highest of all gifts, that of a disposition to humanity, and we may call beauty our second creator. In these letters Schiller spoke out the mildest and highest sentiments on art, and in his paper on Simple and Sentimental Poetry (1795) he constructs the ideal of the perfect poet. This is by far the most fruitful of Schiller's essays in its results. It has much that is practically applicable, and contains a very able estimate of German poetry. The writing is also very pointed and telling, because it is based upon actual perceptions, and it is interesting because the contrast drawn out throughout it between the simple and the sentimental has been referred to his own contrast with Goethe. He also wished to vindicate modern poetry, which Goethe seemed to wish to sacrifice to the antique.