The matter or material of which Bruno here speaks is what afterwards was called _extension_, or the extended substance, and the natural forms are the various individual shapes or bodies of nature: both from the transformations of one into the other, and again from the fact that the particular forms come into being and cease to exist, it was argued that there must be an underlying something, material indeed, but different from all the things we know or see, indifferently capable of becoming any one of them, persisting throughout their becoming, their change, and their ceasing to exist,--_i.e._ a permanent reality. [Sidenote: Matter as potentiality.] [Sidenote: First principle or absolute.] Matter, however, meant not only "subject" or substrate, but also "potentiality," or possibility: and we have to consider it in this light also. Everything that exists is therefore _possible_, and the possibility of coming into existence,--"passive potency,"--implies that of bringing into existence--"active potentiality or power"; the one is never without the other, not even in the first principle. Thus the first principle is all that which it has the possibility of being--in it reality and possibility are one; whereas a stone, _e.g._ is not all that it has the possibility of being, for it is not lime, nor vase, nor dust, nor grass. That which is all that it can be, the Absolute, is also all that any other thing is or can be: it embraces all being within itself. Other things are not thus absolute, but limited to one reality at a time, _i.e._ one specific and particular existence. They can be more only through succession and change. "Every possibility and actuality that in the (first) principle is as it were _complicate_, united, one, in other things is _explicate_, dispersed, many. The universe, which is the great _simulacrum_ and image (of the first principle) is--it also--all that which it may be in its kinds and principal members, as containing all matter, to which no element of the whole (the universal) form can be added, in which no phase of that form is ever wanting; but it is not all that which it may be in its differences, its modes, properties, and individuals; thus it is a mere shadow of the first reality, and first potency, and so far in it reality and possibility are not the same absolutely, that no part of it is all that which it may be: besides that, as we have said, the universe is all that it may be only in explicitness, dispersion, distinctness, whereas its _principle_ is so unitedly and indifferently, for in it all is all, and the same, simply, without difference or distinction."[273] [Sidenote: Matter and form are one.] [Sidenote: Matter or substrate of the spiritual world.]