IV. By attribute I understand that which the mind perceives as constituting the very essence of substance.
V. By modes I understand the accidents (affectiones) of substance; or that which is in something else, through which also it is conceived.
VI. By God I understand the being absolutely infinite; that is, the substance consisting of infinite attributes, each of which expresses an infinite and eternal essence.
Explication, I say absolutely infinite, but not in suo genere; for to whatever is infinite, but not in suo genere, we can deny infinite attributes; but that which is absolutely infinite, to its essence pertains everything which implies essence, and involves no negation.
VII. That thing is said to be free which exists by the sole necessity of its nature, and by itself alone is determined to action. But that is necessary, or rather constrained, which owes its existence to another, and acts according to certain and determinate causes.
VIII. By eternity I understand existence itself, in as far as it is conceived necessarily to follow from the sole definition of an eternal thing.
AXIOMS.
I. Everything which is, is in itself, or in some other thing.
II. That which cannot be conceived through another, per aliud must be conceived, per se.
III. From a given determinate cause the effect necessarily follows, and vice versa. If no determinate cause be given, no effect can follow.