Those who first had some suspicion of the intimate connexion between Aesthetic and Logic and conceived Aesthetic as a _Logic of sensible knowledge_, were strangely addicted to applying logical categories to the new knowledge, talking of _aesthetic concepts, aesthetic judgments, aesthetic syllogisms_, and so on. We are less superstitious as regards the solidity of the traditional Logic of the schools, and better informed as to the nature of Aesthetic. We do not recommend the application of Logic to Aesthetic, but the liberation of Logic from aesthetic forms. These have given rise to non-existent forms or categories of Logic, due to the following of altogether arbitrary and crude distinctions. Logic thus reformed will always be _formal_ Logic; it will study the true form or activity of thought, the concept, excluding single and particular concepts. The old Logic is ill called formal; it were better to call it _verbal_ or _formalistic_. Formal Logic will drive out formalistic Logic. To attain this object, it will not be necessary to have recourse, as some have done, to a real or material Logic, which is not a science of thought, but thought itself in the act; not only a Logic, but the complex of Philosophy, in which Logic also is included. The science of thought (Logic) is that of the concept, as that of fancy (Aesthetic) is the science of expression. The well-being of both sciences lies in exactly following in every particular the distinction between the two domains. VI THEORETIC AND PRACTICAL ACTIVITY The intuitive and intellective forms exhaust, as we have said, all the theoretic form of the spirit. But it is not possible to know them thoroughly, nor to criticize another series of erroneous aesthetic theories, without first establishing clearly their relations with another form of the spirit, which is the _practical_ form. [Sidenote] _The will._ This form or practical activity is the _will_. We do not employ this word here in the sense of any philosophical system, in which the will is the foundation of the universe, the principle of things and the true reality. Nor do we employ it in the ample sense of other systems, which understand by will the energy of the spirit, the spirit or activity in general, making of every act of the human spirit an act of will. Neither such metaphysical nor such metaphorical meaning is ours. For us, the will is, as generally accepted, that activity of the spirit, which differs from the mere theoretical contemplation of things, and is productive, not of knowledge, but of actions. Action is really action, in so far as it is voluntary. It is not necessary to remark that in the will to do, is included, in the scientific sense, also what is vulgarly called not-doing: the will to resist, to reject, the prometheutic will, is also action. [Sidenote] _The will as an ulterior stage in respect to knowledge._