The infinite number of worlds is thus made to depend for its proof upon the identity of power and will, of will and knowledge, _i.e._ thought, in God. Whatever is in the mind of God is realised in the universe. Before God past, present, and future are one, present, and eternal;[325] he is unable to change his purpose or to deny himself. What he wills and what he can are one and the same; nor can he do what he wills not, for fate is the Divine will itself. Hence, as he cannot be other than he is, so nothing can be done by him otherwise than as it is done. The nature of God is a simple substance; however many names be predicated of it, they signify, one and all, the same thing.[326] Infinite virtue, if limited neither by itself nor by another, acts by the necessity of its own nature, not by a necessity alien to itself and to its will; it is itself necessity. The necessity by which it acts, therefore, can be frustrated neither from within, by itself, nor from without, by another: not the former, for it cannot be both one thing and another, nor the latter, because its necessity is the law of all other things. There can be nothing which may prevent this nature, necessity, will, power, from proceeding according to its whole power, which is goodness itself, according to its whole goodness, which is power itself, and both are infinite, and diffuse themselves infinitely. Man's liberty of action is expressed imperfectly, and sometimes in an imperfect object, is continually being disturbed by passion and ignorance of things; for if we acted without any disturbance of the will, or course of thought, without ignorance, or passion, then our action would be determined always towards the better of two opposed ends. Before we act we stand between the two ways and deliberate, and at last determine, but in uncertainty and perturbedness of spirit; while God, as in nature most perfect, acts in the one of two ways that is the most fitting. Nor is it an imperfection of nature to be determined in one direction only, away from that which may lead to error. Thus we may not refer the will and action of God to a liberty of this kind, of being equally or unequally disposed to two contradictory volitions or acts--a liberty of indifference--but his liberty is of the kind which is identical with necessity. Over it is nothing greater, in the way of it there is nothing equal, all things in all and throughout all serve it. God's knowledge is not discursive, involves no effort. To be in the mind of God is to be realised (_species concepta deo est effectio resque_). Thus as the perfect monad, he is intrinsically and extrinsically the whole, sustaining all things. There is on the one side infinite goodness and infinite desire for its realisation, on the other infinite desire of being realised; the result must be perfect satisfaction and perfect good. [Sidenote: Abstract ideas.]