Such are: the Understanding of first principles, which, once we have drawn from our sense-experience the ideas of Being, of Cause, of End, etc., enables us to see immediately -- through the power of the active light which is in us by nature -- the self-evident truths on which all our knowledge depends; Science, which enables us to know by demonstration, assigning causes; Wisdom, which enables us to contemplate the first causes, and in which the mind holds all things in the superior unity of a simple glance. These speculative virtues perfect the intellect in its most proper function, in the activity in which it is purely itself; for the intellect as such aims only to know. The intellect acts, indeed its act is, absolutely speaking, life par excellence; but its act is an immanent act which remains wholly within the intellect to perfect it, and through which the intellect, with a limitless voracity, seizes being and draws it into itself -- it eats being and drinks being -- so as "itself to become, in a certain fashion, all things." Thus the speculative order is its proper order; it is at home there. The good or the evil of the subject, the needs and conveniences of the subject, matter little to it; it enjoys being and has eyes only for being.
The practical order is opposed to the speculative order because there man tends to something other than knowledge only. If he knows, it is no longer to rest in the truth, and to enjoy it (frui); it is to use (uti) his knowledge, with a view to some work or some action.
Art belongs to the practical order. It is turned towards action, not towards the pure interiority of knowledge.
There are, it is true, speculative arts, which are at the same time sciences, as, for instance, logic. These scientific arts perfect the speculative intellect, not the practical intellect; but such sciences retain in their mode something of the practical, and are arts only because they imply the making of a work --- this time a work wholly within the mind, and whose sole object is the achievement of knowledge, a work which consists for instance in setting our concepts in order, in framing a proposition or in constructing a reasoning. The fact remains, therefore, that wherever we find art we find some productive operation to be contrived, some work to be made.
Chapter III Making and Doing