The advantages, however, accruing from frequent definitions are very great; at the least they serve to explain what was meant by the persons using the word, whereas sometimes two men confuse each word by using words to which each attaches an opposite or a dissimilar value. Men will talk of "First Cause," and "Intelligent First Cause." Do they know what they mean? I confess I do not, and from the manner in which they use the words, the most charitable conclusion is that they use them because others have done so, and for no worse or better reason. They talk of the "Beauties of Creation," and "Works of the Great Creator." If by creation is meant the origin of existence, then each utterance of the phrase is an absurdity. The human mind is utterly incapable of construing it in thought as possible that the complement of existence has either been increased or diminished. Man can neither conceive nothing becoming something nor something becoming nothing. Definitions.--1. By existence, or substance, I mean that which is in itself and is conceived _per se_--that is, the conception of which does not require the conception of anything else as antecedent to it. Whenever I use the words universe or matter, I use them in the same sense as representing the totality of existence. Existence can only be known in its modes, and these by their attributes. 2. By attribute, I understand that by which I cognize any mode of existence. Hardness, brightness, color, life, form, etc., are attributes of conditional existence. 3. By mode, I understand each cognized condition or accident of existence. 4. By eternity I mean indefinite duration; that is duration which is to me illimitable. 5. By infinity, I mean indefinite extension. The axioms, so far as I shall give them, are in the precise language of Spinoza. "1. Everything which is, is in itself, or in some other thing.. 2. That which cannot be conceived through another _per aliud_, must be conceived _per se_. 3. From a given determinate cause, the effect necessarily follows; and, _vice versa_, if no determinate cause be given, no effect can follow. 4. The knowledge of an effect depends on a knowledge of the cause, and includes it. 5. Things that have nothing in common with each other, can not be understood by means of each other--that is, the conception of one does not involve the conception of the other."