Consequently in the sequel of my researches I shall adopt the course that nature herself follows with man considered from the point of view of æsthetics, and setting out from the two kinds of beauty, I shall rise to the idea of the genus. I shall examine the effects produced on man by the gentle and graceful beauty when its springs of action are in full play, and also those produced by energetic beauty when they are relaxed. I shall do this to confound these two sorts of beauty in the unity of the beau-ideal, in the same way that the two opposite forms and modes of being of humanity are absorbed in the unity of the ideal man. LETTER XVII. While we were only engaged in deducing the universal idea of beauty from the conception of human nature in general, we had only to consider in the latter the limits established essentially in itself, and inseparable from the notion of the finite. Without attending to the contingent restrictions that human nature may undergo in the real world of phenomena, we have drawn the conception of this nature directly from reason, as a source of every necessity, and the ideal of beauty has been given us at the same time with the ideal of humanity. But now we are coming down from the region of ideas to the scene of reality, to find man in a _determinate state_, and consequently in limits which are not derived from the pure conception of humanity, but from external circumstances and from an accidental use of his freedom. But, although the limitation of the idea of humanity may be very manifold in the individual, the contents of this idea suffice to teach us that we can only depart from it by _two_ opposite roads. For if the perfection of man consist in the harmonious energy of his sensuous and spiritual forces, he can only lack this perfection through the want of harmony and the want of energy. Thus, then, before having received on this point the testimony of experience, reason suffices to assure us that we shall find the real and consequently limited man in a state of tension or relaxation according as the exclusive activity of isolated forces troubles the harmony of his being, or as the unity of his nature is based on the uniform relaxation of his physical and spiritual forces. These opposite limits are, as we have now to prove, suppressed by the beautiful, which re-establishes harmony in man when excited, and energy in man when relaxed; and which, in this way, in conformity with the nature of the beautiful, restores the state of limitation to an absolute state, and makes of man a whole, complete in himself.