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6th Obseru. Where we cannot find out the essence or effential difference of any species or kinds of beings that we would define, we mult content ourselves with a collection of such chief parts or properties of it, as may best explain it so far as it is known, and best distinguish it from other things : fo a marigold is a flower which hath many long yellow leaves, round a little knot of seeds in the midst, with such a peculiar stalk, &c. So if we would define silver, we say it is a white and hard metal, next in weight to gold: if we would define an elder-tree, we might say it is one among the leffer trees, whose younger branches are soft and full of pith, whose leaves are jagged or indented, and of such a particular shape, and it bears large clusters of small black berries : so we must define water, earth, ftone, a lion, an eagle, a serpent, and the greatest part of natural beings, by a collection of those properties, which according to our obfervation diftinguish them from all other things. This is what Mr Locke calls nominal effences, and nominal definitions. And indeed since the essential differences of the various natural beings or bodies round about us arise from a peculiar shape, foze, motion, and situation of the small particles of which they are composed, and since we have no sufficient method to inform us what there are, we must be contented with such a sort of definition of the bodies they compose..
Here note, that this sort of definition, which is made up of a mere collection of the most remarkable parts or properties, is called an imperfect definition or a dę
cription; whereas the definition is called perfect, when it is composed of the effential difference, added to the general nature or genus. ,
7th Observ. The perfect definition, of any being always includes the definition of the name whereby it is called, for it informs us of the sense or meaning of that word, and shews us what idea that word is affixed to : .but the definition of the names does by no means include a perfect definition of the thing; for as we have said before, a mere synonymous word a negation of the contrary, or the mention of any one or two distinguishing, properties of the thing may be a sufficient definition of the name. Yet in those cases where the effential difference or essence of a thing is unknown, there a definition of the name by the chief properties, and a defcription of the thing are much the same.
And here I think it necessary to take notice of one general sentiment, that seems, to run through that excellent performance, Mr Locke's essay of human underitanding, and that is, " That the effences of things are utterly unknown to us, and therefore all our pretences to distinguish the effences of things can reach no farther than mere nominal effences; or a collec: tion of such properties as we know; to some of which we affix particular names, and others. we bundle up, feveral together, under one name : and that all our attempts to rank beings into different kinds of species can reach no-farther than to make mere nominal species : and therefore our definitions of things are but mere nominal descriptions or definitions of the name.”
Now, that we may do justice to this great author, we ought to consider that he confines this sort of difcourse only to the effence of simple ideas; and to the essence of substances, as appears evident in the fourth and fixth chapters of his third book; for he allows the names of mixed modes always to signify the real effences of their species, chap. V. and he acknowledges artificial things to have real distinct species : and that in the distinction of their effences, there is generally "less confusion and uncertainty than in natural, chap. VI. Sect. 40, 41. though it must be confessed that he scarce makes any distinction between the definition of the name, and the definition of the thing, as chap. - IV. and sometimes the current of his discourse decries the knowledge of effences in such general terms, as may justly give occalion to mistake.
It must be granted, that the eflence of most of our fimple ideas, and the greatest part of particular natural fubstances are much unknown to us; and therefore the eilintial difference of fenfible qualities, and of the yarious kinds of bodies. (as I have said before) lie beyond the reach of our understandings : we know not what makes the primary real inward distinctions between red, green, sweet, four, on between, wood, iron, oil, stone, fire, water, flesh, clay, in their general natures, nor do we know what are the inward and prime di. stinctions between all the particular kinds or species in the vegetable, animal, mineral, metallic, or liquid world of things. See Philosoph. eflays. eff. xi. sect. I.
But still there is a very large field for the knowledge of the essences of things, and for the use of perfect definitions amongst our complex ideas, the modal appearances and changes of nature, the works of art, the matters of science, and all the affairs of the civil, the moral and the religious life; and indeed it is of much more importance to all mankind to have a better acquaintance with the works of art for their own livelihood and daily use, with the affairs of morality for their behaviour in this world, and with the matters of religion, that they may be prepared for the world to come, than to be able to give a perfect definition of the works of nature.
If the particular elences of natural bodies are unknown to us, we may yet be good philosophers, good artists, good neighbours, good subjects, and good christians without that knowledge, and we have just reason to be content. A
Now that the essences of some of the modal appearances and changes in nature, as well as things of art, science and morality are sufficiently known to us to make perfect definitions of them, will appear by the specimen of a few definitions of these things.
Motion is a change of place. Swiftness is the passing over a long space in a short time. A natural day is the time of one alternate revolution of light and darkness, or it is the duration of twenty-four hours. An eclipse of the sun is a defect in the sun's transmission of light to us by the moon interpofing. * Snow is congealed vapour. * Hail is congealed rain. An * island is a piece of land rising above the surrounding water, An * hill is an elevated part of the earth, and a * grove
* Note, Island, hill, grove, are not designed here in their more remote and substantial natuies (if I may fo express it) or as the matter of them is earth; for in this lenie we know not their essence, but only as considered in their modal appearances, whereby one part of is a piece of ground thick set with trees. An house is a building made to dwell in. A cottage is a mean house in the country.: A fupper is that meal which we make in the evening. A triangle is a figure composed of three sides. A gallon is a measure containing eight pints. A porter is a man who carries burdens for hire. A king is the chief ruler in a kingdom. Veracity is the conformity of our words to our thoughts. Covetousness is an exceflive love of money, or other possessions. Killing is the taking away the life of an animal. Murder is the unlawful killing of a man. Rhetoric is the art of fpeaking in a manner fit to perfuade. Natural philosophy is the knowledge of the properties of bodies and the various effects of them, or it is the knowledge of the various appearances in na. ture, and their causes; and logic is the art of using our reason well, 8c.
Thus you see the essential differences of various beings may be known, and are borrowed from their qualities and properties, their causes, effects, objects, adjunct, ends, &c. and indeed as infinitely various as the eflences of things are, their definitions must needs have very various forms.
After all it must be confessed, that many logicians and philosophers in the former ages, have made too great a bustle about the exactness of their definitions of things, and entered into long fruitless controversies and very ridiculous debates in the several sciences about adjusting the logical formalities of every definition : whereas that sort of wrangling is now grown very justly contemptible, since it is agreed that true learn. ing and the knowledge of things depends much more upon a large acquaintance with their various properties, causes, effects, subject, object, ends and defigns, than it does upon the formal and scholastic niceties of genus and difference.
earth is distinguished from another. hail, &c.
The famte may be said of fnow,
TTAVING dwelt so long upon the first rule to Il direct our conceptions, and given an account of the definition both of names and things in order to gain clear and distinct ideas, we make haste now to the lecond rule to guide your conceptions, and that is, conceive of things completely in all their parts.
All parts have a reference to some whole : now there 13 an old distinction which logical writers make of a whole and its parts into four several kinds, and it may be proper just to mention them here.
1. There is a metaphysical whole, when the effence of a thing is said to consist of two parts, the genus and the difference, that is, the general and the special nature, which being joined together make up a defini. tion. This has been the fubject of the foregoing sections.
2. There is a mathematical whole which is better called integral, when the several parts, which go to make up the whole, are really diftin&t from one another, and each of them may sablist apart. . So the head, the limbs and the trunk are the integral parts of an animal body ; fo units are the integral parts of any large number; so these discourses which I have written concerning perception, judgment, reasoning and disposition are the four integral parts of logic. This fort of parts goes to make up the completeness of any fubject, and this is the chief and most direct matter of our discour fe in this section
3. There is a physical or effential whole, which is usually made to fignify and include only the two eflential parts of man, body and soul : but I think the sense of it may be better altered, or at least enlarged, and so include all the effential modes, attributes or properties which are contained in the comprehension of any idea. This shall be the subject of discourse under the third Tule to direct our conceptions.