25.  Third argument.[Note:  Vide sect. iii. and vii.]—­Refutation of Locke.—­All our ideas, sensations, notions, or the things which we perceive, by whatsoever names they may be distinguished, are visibly inactive—­there is nothing of power or agency included in them.  So that one idea or object of thought cannot produce or make any alteration in another.  To be satisfied of the truth of this, there is nothing else requisite but a bare observation of our ideas.  For, since they and every part of them exist only in the mind, it follows that there is nothing in them but what is perceived:  but whoever shall attend to his ideas, whether of sense or reflexion, will not perceive in them any power or activity; there is, therefore, no such thing contained in them.  A little attention will discover to us that the very being of an idea implies passiveness and inertness in it, insomuch that it is impossible for an idea to do anything, or, strictly speaking, to be the cause of anything:  neither can it be the resemblance or pattern of any active being, as is evident from sect. 8.  Whence it plainly follows that extension, figure, and motion cannot be the cause of our sensations.  To say, therefore, that these are the effects of powers resulting from the configuration, number, motion, and size of corpuscles, must certainly be false. [Note:  Vide sect. cii.]

26.  Cause of ideas.—­We perceive a continual succession of ideas, some are anew excited, others are changed or totally disappear.  There is therefore some cause of these ideas, whereon they depend, and which produces and changes them.  That this cause cannot be any quality or idea or combination of ideas, is clear from the preceding section.  I must therefore be a substance; but it has been shown that there is no corporeal or material substance:  it remains therefore that the cause of ideas is an incorporeal active substance or Spirit.

27.  No idea of spirit.—­A spirit is one simple, undivided, active being—­as it perceives ideas it is called the understanding, and as it produces or otherwise operates about them it is called the will.  Hence there can be no idea formed of a soul or spirit; for all ideas whatever, being passive and inert (vide sect. 25), they cannot represent unto us, by way of image or likeness, that which acts.  A little attention will make it plain to any one, that to have an idea which shall be like that active principle of motion and change of ideas is absolutely impossible.  Such is the nature of spirit, or that which acts, that it cannot be of itself perceived, but only by the effects which it PRODUCETH.  If any man shall doubt of the truth of what is here delivered, let him but reflect and try if he can frame the idea of any power or active being, and whether