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to be (without knowing what it is) the substratum to those simple ideas we have from without; and the other supposed (with a like ignorance of what it is to be the substratum to those operations we experiment in ourselves within. It is plain, then, that the idea of corporeal substance in matter, is as remote from our conceptions and apprehensions, as that of spiritual substance or spirit : and therefore, from our not having any notion of the substance of spirit, we can no more conclude its nonexistence, than we can, for the same reason, deny the existence of body; it being as rational to affirm there is no body, because we have no clear and distin&t idea of the subjlance of matter, as to say there is no spirit, because we have no clear and distinct idea of the substance of a spirit.

$ 6. Of the forts of Substances. WHATEVER, therefore, be the secret abstract nature of substance in general, all the ideas we have of particular diNinet forts of substances are nothing but several combinations of limple ideas, co-existing in such, though unknown, cause of their union, as makes the whole sublist of itself. It is by such combinations of Gimple ideas, and nothing else, that we represent particular sorts of subJiances to ourselves; such are the ideas we have of their several species in our minds; and such only do we, by their specific name, signify to others, v. g. man, borse, fun, water, iron : upon hearing which words, every one who understands the language, frames in his mind a combination of those several limple ideas which he has usually observed, or fancied to exist together under that denomination; all which he supposes to rest in, and be, as it were, adherent to that unknown common subject, which inheres not in any thing else. Though, in the mean time, it be manifest, and every one upon inquiry into his own thoughts will find that he has no other idea of any substance, v. g. let it be gold, horse, iron, man, vitriol, bread, but what he has barely of those fenfible qualities which he supposes to inhere, with a supposition of such a fubftratum, as gives, as it were, a support to those qualities or simple ideas which he has observed to exist united together. Thus, the idea of the fun, what is it but an aggregate of those several simple ideas, bright, hot, roundish, having a constant regular motion, at a certain distance from us, and perhaps some other? as he who thinks and discourses of the sun, has been more or less accurate in observing those senfible qualities, ideas, or properties, which are in that thing which he calls the sun. 7. Power, a great part of our complex Ideas of Subo

fances. For he has the perfectelt idea of any of the particular forts of substances, who has gathered and put together most of those fimple ideas which do exist in it, among which are to be reckoned its active powers and passive capacities; which, though not simple ideas, yet in this refpect, for brevity fake, may conveniently enough be reckoned amongst them. Thus, the power of drawing iron is one of the ideas of the complex one of that substance we call a load one ; and a power to be so drawn, is a part of the complex one we call iron : which powers pass for inherent qualities in those subjects. Because every substance, being as apt, by the powers we observe in it, to change fome sensible qualities in other subjects, as it is to produce in us those simple ideas which we receive immediately from it, does, by those new sensible qualities introduced into other subjects, discover to us those powers which do thereby mediately affect our senses, as regularly as its sensible qualities do it immediately: 9. g. we immediately, by our senses, perceive in fire its heat and colour, which are, if rightly confidered, nothing but powers in it to produce those ideas in us : We also, by our senses, perceive the colour and brittieness of charcoal, whereby we come by the knowledge of another power in fire, which it has to change the colour and consistency of wood. By the former fire immediately, by the latter it mediately discovers to us these several powers, which therefore we look upon to be a part of the qualities of fire, and so make them a part of the complex ideas of it. For all those powers that we take cognisance of, terminating only in the al

teration of some fenfible qualities in those subjects on which they operate, and so making them exhibit to us new fenfible ideas; therefore it is that I have reckoned these powers amongst the simple ideas, which make the complex ones of the sorts of substances ; though these powers, considered in themselves, are truly complex idias. And in this looser sense I crave leave to be understood, when I name any of these potentialities amongst the simple ideas, which we recollect in our minds, when we think of particular subllances. For the powers that are severally in them, are neceilary to be considered, if we will have true diftin&t notions of the several forts of fubļtances.

$ 8. And wky. Nor are we to wonder, that powers make a great part of our complex ideas of fubfiances, lince their secondary qualities are those, which in most of them sirve principally to distinguish substances one from another, and commonly make a conGiderable part of the complex idea of the several sorts of them. For our senses failing us in the discovery of the bulk, texture, and figure of the minute parts of bodies, on which their real constitutions and differences depend, we are fain to make use of their secondary qualities as the characteristical notes and marks, whereby to frame ideas of them in our minds, and distinguish them one from another; all which fecondary qualities, as has been shown, are nothing but bare powers : For the colour and taste of opium are, as well as its soporific or anodyne virtues, mere powers depending on its primary qualities, whereby it is fitted to produce different operations on different parts of our bodies. $9. Three forts of Ideas make our complex enes of

Substances. The Ideas that make our complex ones of corporeal fubitane ces, are of these three forts. First, The ideas of the primary qualities of things, which are discovered by our senses, and are in them even when we perceive them not; such are the bulk, figure, number, situatica, and motion of the parts of bodies, which are really in

them, whether we take notice of them or no. Secondly, The sensible secondary qualities, which, depending on these, are nothing but the powers those substances have to produce several ideas in us by our senses; which ideas are not in the things themselves, otherwise than as any thing is in its cause. Thirdly, The aptness we consider in any fubftance to give or receive such alterations of primary qualities, as that the fubftance fo altered thould produce in us different ideas from what it did before ; these are called active and pallive powers : All which powers, as far as we have any notice or notion of them, terminate only in sensible fimple ideas. For whatever alteration a loadsone has the power to make in the minute particles of iron, we should have no notion of any power it had at all to operate on iron, did not its senlible motion discover it: and I doubt not, but there are a thoufand changes, that bodies we daily handle have a power to cause in one another, which we never fulpect, because they never appear in sensible effects. Ø 10. Powers make a great part of our complex Ideas of

Substances. Powers therefore justly make a great part of our complex ideas of fubfiances. He that will examine his complex idea of gold, will find several of its ideas that make it up, to be only powers: as the power of being melted, but of not spending itself in the fire; of being diffolved in ag, regia ; are ideas as necessary to make up our complex idea of gold, as its colour and weight: which, if duly considered, are also nothing but different powers. For to speak truly, yellowness is not actually in gold, but is a power in gold to produce that idea in us by our eyes, when placed in a due light : And the heat, which we cannot leave out of our idea of the fun, is no more really in the sun, than the white colour it introduces into war. Thefe are both equally powers in the fun, operating, by the motion and figure of its insensible parts, so on a man, as to make him have the idea of heat ; and so on wax, as to make it capable to produce in a man the idea of white.

$11. The noru fecondary Qualities of Bodies would dif

appear, if we could discover the primary ones of their

minute parts. Had we senses acute enough to discern the minute. particles of bodies, and the real constitution on which their senable qualities depend, I doubt not but they would produce quite different ideas in us; and that which is now the yellow colour of gold would then disappear, and instead of it we should see an admi. rable texture of parts of a certain size and figure. This microscopes plainly discover to us: For what to our naked eyes produces a certain colour, is, by thus aug. menting the acuteness of our senses, discovered to be quite a different thing; and the thus altering, as it were, the proportion of the bulk of the minute parts of a coloured object to our usual light, produces different ideas from what it did before. Thus sand or pounded glass, which is opaque, and white to the naked eye, is pel. lucid in a microscope ; and a hair seen this way loses its former colour, and is in a great measure pellucid, with a mixture of some bright sparkling colours, such as appear from the refraction of diamonds, and other pellucid bodies. Blood, to the naked eye, appears all red; but by a good microscope, wherein its lesser parts appear, shows only some few globules of red, swimming in a pellucid liquor; and how these red globules would appear, if glasses could be found that yet could magnify them 1000, or 10,000 times more, is uncertain.

$ 12. Our Faculties of Discovery suited to our State. The infinite wise Contriver of us, and all things about us, hath fitted our senses, faculties, and organs, to the conveniencies of life, and the business we have to do here. We are able, by our senses, to know and diftinguish things, and to examine them so far, as to apply them to our uses, and several ways to accommodate the exigencies of this life. We have insight enough into their admirable contrivances and wonderful effects, to admire and magnify the wisdom, power, and goodnefs of their Author. Such a knowledge as this, which is suited to our present condition, we want not faculties

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