their life and work, they show forth and preach the majesty of this first principle and cause."[250] Thus the starting-point of Bruno's mature philosophy is _nature_ as the vestige or imprint of divinity, and divinity is considered only "as nature itself or as reflected in nature": the presence of a transcendent principle above and beyond nature is, indeed, premised to the discussion of the _Causa_, but it is no longer admitted that its study falls within the philosopher's scope, nor does it ever hamper or in any way influence the course of the argument. So far from that, we find, at the completion of the dialogue, that we have arrived at an _immanent_ principle or divinity, which renders the _transcendent_ superfluous. [Sidenote: Principle: Cause.] The purpose of the _Causa_,[251] Bruno's first purely philosophical work, was to determine what are the creative and constitutive principles of the natural world,--its efficient cause, its end, its form, its matter, and its unity; or, in other words, to lay down the "foundations of knowledge," to give an outline-picture of reality the details of which it was left to experience and observation to fill in. Bruno begins by laying down certain distinctions, which, however, do not, in the end, prove very binding. First, a _principle_ (_principio_) is that which enters, intrinsically, into the constitution of a thing, while a _cause_ concurs from without in its production; thus, matter and form, which are principles rather than causes, are the elements of which a thing is composed and into which it is resolved. A cause, on the other hand, remains outside of the resultant object--for example, the efficient, creating cause, and the end or final cause for which the thing is ordained. Principle is the more general term, for "in Nature, not everything that is principle, is also cause: the point is principle of the line, not cause; the instant, of the event; the starting-point, of the movement; the premisses, of the argument."[252] God is both principle and cause, but from different points of view: "He is first _principle_ in so far as all things are posterior to him in nature, duration, or dignity; he is first _cause_ in so far as all things are distinguished from him as effect from efficient, thing produced from producer. The points of view are different, for not always is the prior and more worthy a cause of that which is posterior and less worthy; and not always is the cause prior and more worthy than that which is caused."[253] There are really two marks of a principle given by Bruno, priority in worth, and internality; but, generally, a principle is that without which a thing could not come into being, and which if taken away would take away also the being of the thing. To a cause the latter half of this description would not apply, as it remains outside of the effect. Thus God as principle is immanent in all things, and is the higher source from which they proceed. This twofold