ference to any archetypes, men may, if they please, exactly know the ideas that go to each composition, and so both use these words in a certain and undoubted signification, and perfectly declare, when there is occasion, what they stand for. This, if well considered, would lay great blame on those, who make not their discourses about moral things very clear and distinct. For since the precise signification of the names of mixed modes, or, which is all one, the real essence of each species is to be known, they being not of nature's but man's making, it is a great negligence and perverseness to discourse of moral things with uncertainty and obscurity; which is more pardonable in treating of natural substances, where doubtful terms are hardly to be avoided, for a quite contrary reason, as we shall see by and by. §. 16. Upon this ground it is, that I am Morality ca- bold to think, that morality is capable of pable of demonstration, demonstration, as well as mathematicks: since the precise real essence of the things moral words stand for may be perfectly known; and so the congruity and incongruity of the things themselves. be certainly discovered; in which consists perfect knowledge. Nor let any one object, that the names of substances are often to be made use of in morality, as well as those of modes, from which will arise obscurity. For as to substances, when concerned in moral discourses, their divers natures are not so much inquired into, as supposed; v, g. when we say that man is subject to law, we mean nothing by man, but a corporeal rational creature: what the real essence or other qualities of that creature are, in this case, is no way considered, And therefore, whether a child or changeling be a man in a physical sense, may amongst the naturalists be as dis putable as it will, it concerns not at all the moral man, as I may call him, which is this immoveable unchangeable idea, a corporeal rational being. For were there a monkey, or any other creature to be found, that has the use of reason to such a degree as to be able to understand general signs, and to deduce consequences about general ideas, he would no doubt be subject to law, and in that sense be a man, how much soever he differed in shape from from others of that name. The names of substances, if they be used in them as they should, can no more disturb moral than they do mathematical discourses: where, if the mathematician speaks of a cube or globe of gold, or any other body, he has his clear settled idea which varies not, though it may by mistake be applied to a particular body to which it belongs not. Definitions can make moral dis. courses clear. §. 17. This I have here mentioned by the by, to show of what consequence it is for men, in their names of mixed modes, and consequently in all their moral discourses, to define their words when there is occasion: since thereby moral knowledge may be brought to so great clearness and certainty. And it must be great want of ingenuity (to say no worse of it) to refuse to do it: since a definition is the only way whereby the precise meaning of moral words can be known; and yet a way whereby their meaning may be known certainly, and without leaving any room for any contest about it. And therefore the negligence or perverseness of mankind cannot be excused, if their discourses in morality be not much more clear than those in natural philosophy: since they are about ideas in the mind, which are none of them false or disproportionate: they having no external beings for the archetypes which they are referred to, and must correspond with. It is far easier for men to frame in their minds an idea which shall be the ftandard to which they will give the name justice, with which pattern so made, all actions that agree shall pass under that denomination; than, having seen Aristides, to frame an idea that shall in all things be exactly like him; who is as he is, let men make what idea they please of him. For the one, they need but know the combination of ideas that are put together in their own minds; for the other, they must inquire into the whole nature, and abstruse hidden conftitution, and various qualities of a thing existing without them. And is the §. 18. Another reason that makes the defining of mixed modes so necessary, espe only way. cially of moral words, is what I mentioned a little before, viz. that it is the only way whereby the T4 signi signification of the most of them can be known with certainty. For the ideas they stand for, being for the most part such whose component parts no where exist together, but scattered and mingled with others, it is the mind alone that collects them, and gives them the union of one idea: and it is only by words, enumerating the several simple ideas which the mind has united, that we can make known to others what their names stand for; the assistance of the senses in this case not helping us, by the proposal of sensible objects, to show the ideas which our names of this kind stand for, as it does often in the names of sensible simple ideas, and also to some degree in those of substances. 3. In substances, by; "defining. §. 19. Thirdly, for the explaining the signification of the names of substances, as showing and they stand for the ideas we have of their distinct species, both the fore-mentioned ways, viz. of showing and defining, are requisite in many cases to be made use of. For there being ordinarily in each sort some leading qualities, to which we suppose the other ideas, which make up our complex idea of that species, annexed; we forwardly give the specifick name to that thing, wherein that characteristical mark is found, which we take to be the most distinguishing idea of that species. These leading or characteristical (as I may call them) ideas, in the sorts of animals and vegetables, are (as has been before remarked, ch. vi. §. 29. and ch. ix. §. 15.) mostly figure, and in inanimate bodies, colour, and in some both together. Now, Ideas of the leading qua. lities of substances are best got by showing. §. 20. These leading sensible qualities are those which make the chief ingredients of our specifick ideas, and consequently the most observable and invariable part in the definitions of our specifick names, as attri buted to sorts of substances coming under our knowledge, For though the sound man, in its own nature, be as apt to signify a complex idea made up of animality and rationality, united in the same subject, as to signify any other combination; yet used as a mark to stand for a sort of creatures we count of our own kind, perhaps, the outward shape is as necessary to be taken into our complex idea, signified by the word man, as any other we find in it: and therefore why Plato's "animal implume bipes latis unguibus" should not be a good definition of the name man, standing for that sort of creatures, will not be easy to show: for it is the shape, as the leading quality, that seems more to determine that species, than a faculty of reasoning, which appears not at first, and in some never. And if this be not allowed to be so, I do not know how they can be excused from murder, who kill monstrous births, (as we call them) because of an unordinary shape, without knowing whether they have a rational soul or no; which can be no more discerned in a well-formed than illshaped infant, as soon as born. And who is it has informed us, that a rational soul can inhabit no tenement, unless it has just such a sort of frontispiece; or can join itself to, and inform no sort of body but one that is just of such an outward structure? §. 21. Now these leading qualities are best made known by showing, and can hardly be made known otherwise. For the shape of an horse, or cassuary, will be but rudely and imperfectly imprinted on the mind by words; the sight of the animals doth it a thousand times better: and the idea of the particular colour of gold is not to be got by any description of it, but only by the frequent exercise of the eyes about it, as is evident in those who are used to this metal, who will frequently distinguish true from counterfeit, pure from adulterate, by the sight; where others (who have as good eyes, but yet by use have not got the precise nice idea of that peculiar yellow) shall not perceive any difference. The like may be said of those other simple ideas, peculiar in their kind to any substance; for which precise ideas there are no peculiar names. The particular ringing sound there is in gold, distinct from the sound of other bodies, has no particular name annexed to it, no more than the particular yellow that belongs to that metal. §. 22. But because many of the simple ideas that make up our specifick ideas of substances, are powers which lie not obvious to our senses in the things as they The ideas of their powers best by definition. ordinarily appear; therefore in the signification of our names of substances, some part of the signification will be better made known by enumerating those simple ideas, than by showing the substance itself. For he that to the yellow shining colour of gold got by sight, shall, from my enumerating them, have the ideas of great ductility, fusibility, fixedness, and solubility in aq. regia, will have a perfecter idea of gold, than he can have by seeing a piece of gold, and thereby imprinting in his mind only its obvious qualities. But if the formal constitution of this shining, heavy, ductile thing (from whence all these its properties flow) lay open to our senses, as the formal constitution, or essence of a triangle does, the signification of the word gold might as easily be ascertained as that of triangle. A reflection rits. §. 23. Hence we may take notice how on the know much the foundation of all our knowledge ledge of spi- of corporeal things lies in our senses. For how spirits, separate from bodies (whose knowledge and ideas of these things are certainly much more perfect than ours) know them, we have no notion, no idea at all. The whole extent of our knowledge or imagination reaches not beyond our own ideas limited to our ways of perception. Though yet it be not to be doubted that spirits of a higher rank than those immersed in flesh, may have as clear ideas of the radical constitution of substances, as we have of a triangle, and so perceive how all their properties and operations flow from thence: but the manner how they come by that knowledge exceeds our conceptions. 4. Ideas also of substances must be conformable to things. §. 24. But though definitions will serve to explain the names of substances as they stand for our ideas; yet they leave them not without great imperfection as they stand for things. For our names of substances being not put barely for our ideas, but being made use of ultimately to represent things, and so are put in their place; their signification must agree with the truth of things as well as with men's ideas. And therefore in substances we are not always to rest in the ordinary complex idea, commonly received as the signification of |