The argument concerning the possible substantiality of the case or individual thing is relatively simple. Suppose an attribute or kind, _A_, of which there are cases _am_{1}, _am_{2}, _am_{3}, etc. The number of cases is never involved in the nature of the kind, as is seen for example in the fact that the definition of triangle prescribes no special number of individual triangles. Hence _am_{1}, _am_{2}, _am_{3}, etc., must be explained by something outside of their nature. Their being cases of _A_ does not account for their existing severally. This is Spinoza's statement of the argument that individual events, such as motions or sensations, are not self-dependent, but belong to a context of like events which are mutually dependent. The question of the attribute is more difficult. Why may not an attribute as a complete domain of interdependent events, itself be independent or substantial? Spinoza's predecessor, Descartes, had maintained precisely that thesis in behalf of the domain of thought and the domain of space. Spinoza's answer rests upon the famous ontological argument, inherited from scholasticism and generally accepted in the first period of modern philosophy. The evidence of existence, he declares, is clear and distinct conceivability. "For a person to say that he has a clear and distinct--that is, a true--idea of a substance, but that he is not sure whether such substance exists, would be the same as if he said that he had a true idea, but was not sure whether or no it was false."[314:6] Now we can form a clear and distinct idea of an absolutely infinite being that shall have all possible attributes. This idea is a well-recognized standard and object of reference for thought. But it is a conception which is highly qualified, not only through its clearness and distinctness, but also through its abundance of content. It affirms itself therefore with a certainty that surpasses any other certainty, because it is supported by each and every other certainty, and even by the residuum of possibility. If any intelligible meaning be permitted to affirm itself, so much the more irresistible is the claim of this infinitely rich meaning. Since every attribute contributes to its validity, the being with infinite attributes is infinitely or absolutely valid. The conclusion of the argument is now obvious. If the being constituted by the infinite attributes exists, it swallows up all possibilities and exists exclusively. [Sidenote: The Limits of Spinoza's Argument for God.]