The method by which Bruno sought to know the nature of the souls of the worlds is one which the course of modern philosophy has rendered familiar to us in other connections. It rests upon the argument from the part to the whole. "Whatever we find in a part of the world belongs, in a higher sense (_sublimius_), to the whole, and must be attributed to it. All the capacities of each part are attributed to the whole--that is, their perfections and activities, not the qualities they possess as parts, and as less than the whole in any respect." Thus the hindrances to which lesser individuals are exposed, the necessity of taking in and giving out matter as their forms change, exist in the greater individual in a minimal degree. But in all parts of the earth Bruno found signs of life, sensation, and even intelligence. Stones of different kinds were universally believed to have a kind of sensibility and instinct: to move of their own accord, attract other bodies to themselves, act upon our human spirits and senses. The phenomena of animal instinct were a constant object of interest to Bruno, who saw in them the expression of a deeper intelligence than the merely human. It is true the observations on which he built may not always have been exact; but that does not detract from the value of his principle. Thus the porcupine (_istrix_) moved his admiration because of its careful storing up of a stock of darts in its back, with which to protect its life; it could, with unerring aim, cast one at its enemy, hearing, it is said, with its skin; and its precision far surpassed all that the cunning of man, with his many instruments, could do. With perfect skill it threw its darts, yet sparingly, so that no part of its body was ever defenceless, the spirit directing all its actions from one centre, to which, from every part of the body, report was made! "With how much higher reason will the _star_ be endowed, of the body of which animals are made, by whose spirit they flourish? So the earth from one centre directs all its actions and those of its parts; it never errs, neither it nor any of the worlds which dwell in the immeasurable ether."[373]