170. All that does not imply a contradiction must be affirmed of the infinite being. That which is absurd is not a perfection. 171. Analyzing indeterminate and intuitive ideas, we find that all the reality contained in them is affirmed of God. 172. The absolutely infinite being must be intelligent. 173. Intelligence is a perfection which does not imply contradiction. 174. Will and liberty must also be found in the absolutely infinite being. 175. The indeterminate idea of the infinite is favored by the combination of the ideas of being and not-being. 176. The idea of an absolutely infinite being consists in the idea of a union of all being that involves no contradiction. 177. The indeterminate idea of a real infinite being, or of God, is formed from the idea of an absolutely infinite being, combined with the intuitive ideas of intelligence, will, liberty, causality, and all others that can be conceived without imperfection, in any infinite degree. BOOK NINTH. ON SUBSTANCE. CHAPTER I. NAME AND GENERAL IDEA OF SUBSTANCE. 1. What is substance? Have we a clear and distinct idea of it? The disputes of philosophers concerning the idea of substance and the continual applications which we make of it, prove two things: first, that the idea of substance exists; and secondly, that its clearness and distinctness are not all that could be desired. A mere name, containing no idea, could not so strongly draw the attention of all philosophers, nor be used so generally, even in ordinary language; a clear and distinct idea could not give occasion to so much dispute. 2. The importance of this idea may be seen in the results to which philosophers are led, according to the way in which they explain it. The entire system of Spinosa is founded on wrong definition of substance. 3. In the present question as in many others, it does not seem to be the shortest way to begin with a definition, unless the thing defined is only a name: to define a thing is to explain it, and we cannot explain it if we are ignorant of what it is, and we are ignorant, or are supposed to be ignorant of this, when we enter on investigations in order to ascertain what it is. If philosophers, at the beginning of their treatises, would not say, substance is this, but only, this is what I understand by substance, they would escape a number of difficulties.