The choice between these terms seems to be still unsettled, and no one seems to know rightly on what grounds it should be decided, and yet the thing is simple. We have already said elsewhere that “knowing” is something different from “doing.” The two are so different that they should not easily be mistaken the one for the other. The “doing” cannot properly stand in any book, and therefore also Art should never be the title of a book. But because we have once accustomed ourselves to combine in conception, under the name of theory of Art, or simply Art, the branches of knowledge (which may be separately pure sciences) necessary for the practice of an Art, therefore it is consistent to continue this ground of distinction, and to call everything Art when the object is to carry out the “doing” (being able), as for example, Art of building; Science, when merely knowledge is the object; as Science of mathematics, of astronomy. That in every Art certain complete sciences may be included is intelligible of itself, and should not perplex us. But still it is worth observing that there is also no science without a mixture of Art. In mathematics, for instance, the use of figures and of algebra is an Art, but that is only one amongst many instances. The reason is, that however plain and palpable the difference is between knowledge and power in the composite results of human knowledge, yet it is difficult to trace out their line of separation in man himself. 2. DIFFICULTY OF SEPARATING PERCEPTION FROM JUDGMENT. (ART OF WAR.) All thinking is indeed Art. Where the logician draws the line, where the premises stop which are the result of cognition—where judgment begins, there Art begins. But more than this even the perception of the mind is judgment again, and consequently Art; and at last, even the perception by the senses as well. In a word, if it is impossible to imagine a human being possessing merely the faculty of cognition, devoid of judgment or the reverse, so also Art and Science can never be completely separated from each other. The more these subtle elements of light embody themselves in the outward forms of the world, so much the more separate appear their domains; and now once more, where the object is creation and production, there is the province of Art; where the object is investigation and knowledge Science holds sway.—After all this it results of itself that it is more fitting to say Art of War than Science of War. So much for this, because we cannot do without these conceptions. But now we come forward with the assertion that War is neither an Art nor a Science in the real signification, and that it is just the setting out from that starting-point of ideas which has led to a wrong direction being taken, which has caused War to be put on a par with other arts and sciences, and has led to a number of erroneous analogies.