1. Having understood what imaginary space is, in which we supposed nothing remaining without us, but all those things to be destroyed, that, by existing heretofore, left images of themselves in our minds; let us now suppose some one of those things to be placed again in the world, or created anew. It is necessary, therefore, that this new-created or replaced thing do not only fill some part of the space above mentioned, or be coincident and coextended with it, but also that it have no dependance upon our thought. And this is that which, for the extension of it, we commonly call _body_; and because it depends not upon our thought, we say is _a thing subsisting of itself_; as also _existing_, because without us; and, lastly, it is called the _subject_, because it is so placed in and _subjected_ to imaginary space, that it may be understood by reason, as well as perceived by sense. The definition, therefore, of _body_ may be this, a _body is that, which having no dependance upon our thought, is coincident or coextended with some part of space_. [Sidenote: Accident defined.] 2. But what an _accident_ is cannot so easily be explained by any definition, as by examples. Let us imagine, therefore, that a body fills any space, or is coextended with it; that coextension is not the coextended body: and, in like manner, let us imagine that the same body is removed out of its place; that removing is not the removed body: or let us think the same not removed; that not removing or rest is not the resting body. What, then, are these things? They are _accidents_ of that body. But the thing in question is, _what is an accident?_ which is an enquiry after that which we know already, and not that which we should enquire after. For who does not always and in the same manner understand him that says any thing is extended, or moved, or not moved? But most men will have it be said that _an accident is something_, namely, some part of a natural thing, when, indeed, it is no part of the same. To satisfy these men, as well as may be, they answer best that define an _accident_ to be _the manner by which any body is conceived_; which is all one as if they should say, _an accident is that faculty of any body, by which it works in us a conception of itself_. Which definition, though it be not an answer to the question propounded, yet it is an answer to that question which should have been propounded, namely, _whence does it happen that one part of any body appears here, another there?_ For this is well answered thus: _it happens from the extension of that body_. Or, _how comes it to pass that the whole body, by succession, is seen now here, now there?_ and the answer will be, _by reason of its motion_. Or, lastly, _whence is it that any body possesseth the same space for sometime?_ and the answer will be, _because it is not moved_. For if concerning the name of a body, that is, concerning a concrete name, it be asked, _what is it?_ the answer