Each attribute is infinite _suo genere_; and it is time that we should know distinctly the meaning which Spinoza attaches to that important word. Out of the infinite number of the attributes of God, two only, he says, are known to us--'extension,' and 'thought,' or 'mind.' Duration, even though it be without beginning or end, is not an attribute; it is not even a real thing. Time has no relation to Being, conceived mathematically; it would be absurd to speak of circles or triangles as any older to-day than they were at the beginning of the world. These and everything of the same kind are conceived, as Spinoza rightly says, _sub quadam specie aeternitatis_. But extension, or substance extended, and thought, or substance perceiving, are real, absolute, and objective. We must not confound extension with body; for though body be a mode of extension, there is extension which is not body, and it is infinite because we cannot conceive it to be limited except by itself--or, in other words, to be limited at all. And as it is with extension, so it is with mind, which is also infinite with the infinity of its object. Thus there is no such thing as creation, and no beginning or end. All things of which our faculties are cognizant under one or other of these attributes are produced from God, and in him they have their being, and without him they would cease to be. Proceeding by steps of rigid demonstration (and most admirably indeed is the form of the philosophy adapted to the spirit of it), we learn that God is the only _causa libera_; that no other thing or being has any power of self-determination; all moves by fixed laws of causation, motive upon motive, act upon act; there is no free will, and no contingency; and however necessary it may be for our incapacity to consider future things as in a sense contingent (see _Tractat. Theol. Polit._ cap. iv., sec. 4), this is but one of the thousand convenient deceptions which we are obliged to employ with ourselves. God is the _causa immanens omnium_; he is not a personal being existing apart from the universe; but himself in his own reality, he is expressed in the universe, which is his living garment. Keeping to the philosophical language of the time, Spinoza preserves the distinction between _natura naturans_ and _natura naturata_. The first is being in itself, the attributes of substance as they are conceived simply and alone; the second is the infinite series of modifications which follow out of the properties of these attributes. And thus all which _is_, is what it is by an absolute necessity, and could not have been other than it is. God is free, because no causes external to himself have power over him; and as good men are most free when most a law to themselves, so it is no infringement on God's freedom to say that he _must_ have acted as he has acted, but rather he is absolutely free because absolutely a law himself to himself.