[Sidenote: Movements of bodies; their soul-principle.] The movements of the earth and of other free-moving bodies are always attributed by Bruno to an "internal principle or _soul_." Movement from without could only take place through direct contact, and the liquid air or ether is too light to move these heavy bodies.[371] "It is taking things by the wrong end to say that the loadstone attracts the iron, the amber the straw, the sun the sunflower. In the iron there is a kind of sense, awakened by a spiritual (_i.e._ a subtly material) virtue diffused from the loadstone, ... and generally everything that desires and has intelligence moves towards the thing desired, converts itself into it as far as possible, beginning with the wish to be in the same place." By the same principle are explained the phenomena of _gravity_, which is defined as impulse towards the place of preservation, such as the earth is to the stone that has formed part of it; its opposite, "_levity_," is impulse away from the contrary or the injurious. "_Gravity_ and _levity_ are nothing but the impulse of parts to their place, where they may either move or be at rest, or to a place through which it is necessary for them to go (in the circular movement of all material things)." Thus the motions of the heavy and the light are merely relative movements; the same kind of motion does not belong always to the same kind of substance or element.[372] The movement of the stars is determined not by considerations of place only, but also by the necessity that bodies of one kind are under of deriving sustenance from those of another,--the suns from the earths and the earths from the suns. It is through the soul that their needs are felt, and the soul directs their movements as does the human soul those of the human body. There are, however, no fixed limits to their movements: they are governed only by the convenience of life, as perceived by the sense and mind, which are inborn in each. By this fantastic principle Bruno explained what he thought to be the fact, that all heavenly bodies whatsoever are in movement; or perhaps we should say he inferred the fact from the principle:--which was first in the order of his thought it would be impossible to know. Like most of his contemporaries he looked upon the conception of a soul in all things with peculiar reverence-- _Porgimus haec paucis, vulgus procul esto prophanum, Ne liceat laico sacrum conscendere montem._