reign idioms into it without neceffity or ufe, and to make it ambiguous where it was not. The diftinctions in the end of the Categories of the four words, prius, fimul, motus, and babere, are all verbal.

The modes or fpecies of prius, according to Ariftotle, are five. One thing may be prior to another; first, in point of time; fecondly, in point of dignity; thirdly, in point of order; and fo forth. The modes of fimul are only three. It feems this word was not used in the Greek with fo great latitude as the other, although they are relative terms.

The modes or species of motion he makes to be fix, to wit, generation, corruption, increase, decrease, alteration, and change of place.

The modes or fpecies of having are eight. 1. Having a quality or habit, as having wisdom. 2. Having quantity or magnitude. 3. Having things adjacent, as having a fword. 4. Having things as parts, as having hands or feet. 5. Having in a

part or on a part, as having a ring on one's finger. 6. Containing, as a cafk is faid to have wine. 7. Poffeffing, as having lands or houses. 8. Having a wife.

Another diftinction of this kind is Ariftotle's diftinction of caufes; of which he makes four kinds, efficient, material, formal, and final. Thefe diftinctions may deserve a place in a dictionary of

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the Greek language; but in English or Latin they adulterate the language. Yet fo fond were the schoolmen of diftinctions of this kind, that they added to Ariftotle's enumeration, an impulfive caufe, an exemplary caufe, and I don't know how many more. We seem to have adopted into English a final caufe; but it is merely a term of art, borrowed from the Peripatetic philofophy, without neceffity or ufe: for the English word end is as good as final caufe, though not fo long nor fo learned.

SECT. 4. On Definitions.

It remains that we make fome remarks on Ariftotle's definitions, which have expofed him to much cenfure and ridicule. Yet I think it must be allowed, that in things which need definition and admit of it, his definitions are commonly judicious and accurate; and had he attempted to define fuch things only, his enemies had wanted great matter of triumph. I believe it may likewife be faid in his favour, that until Locke's effay was wrote, there was nothing of importance delivered by philofophers with regard to definition, beyond what Ariftotle has faid upon that fubject.

He confiders a definition as a fpeech declaring what a thing is. Every thing effential to the thing defined, and nothing more, must be contained in the definition. Now the effence of a thing con

fifts of these two parts: Firft, What is common to it with other things of the fame kind; and, fecondly, What diftinguishes it from other things of the fame kind. The firft is called the genus of the thing, the fecond its fpecific difference. The definition therefore confifts of thefe two parts. And for finding them, we must have recourfe to the ten categories; in one or other of which every thing in nature is to be found. Each category is a genus, and is divided into fo many fpecies, which are diftinguished by their specific differences. Each of thefe fpecies is again fubdivided into fo many fpecies, with regard to which it is a genus. This divifion and fubdivifion continues until we come to the lowest species, which can only be divided into individuals, diftinguished from one another, not by any specific difference, but by accidental differences of time, place, and other circumftances.

The category itself being the highest genus, is in no respect a species, and the loweft fpecies is in no refpect a genus; but every intermediate order is a genus compared with thofe that are below it, and a fpecies compared with thofe above it. To find the definition of any thing, therefore, you must take the genus which is immediately above its place in the category, and the specific difference, by which it is diftinguished from other fpecies of the fame genus. These two make a perfect definition. This I take to be the fubftance of Ariftotle's

ftotle's fyftem; and probably the fyftem of the Pythagorean school before Ariftotle, concerning definition.

But notwithstanding the fpecious appearance of this fyftem, it has its defects. Not to repeat what was before said of the imperfection of the divifion of things into ten categories, the fubdivifions of each category are no lefs imperfect. Ariftotle has given some fubdivifions of a few of them; and, as far as he goes, his followers pretty unanimously take the same road. But when they attempt to go farther, they take very different roads. It is evident, that if the series of each category could be completed, and the divifion of things into categories could be made perfect, ftill the highest genus in each category could not be defined, because it is not a fpecies; nor could individuals be defined, because they have no specific difference. There are alfo many fpecies of things, whofe fpecific difference cannot be expreffed in language, even when it is evident to fenfe, or to the understanding. Thus green, red, and blue, are very diftinct fpecies of colour; but who can exprefs in words wherein green differs from red or blue?

Without borrowing light from the ancient fyftem, we may perceive, that every definition must confift of words that need no definition; and that to define the common words of a language that have no ambiguity, is trifling, if it could be done; the only use of a definition being to give a clear

and

and adequate conception of the meaning of a word.

The logicians indeed diftinguish between the definition of a word, and the definition of a thing; confidering the former as the mean office of a lexicographer, but the last as the grand work of a philofopher. But what they have said about the definition of a thing, if it have a meaning, is beyond my comprehenfion. All the rules of definition agree to the definition of a word; and if they mean by the definition of a thing, the giving an adequate conception of the nature and effence of any thing that exists; this is impoffible, and is the vain boast of men, unconscious of the weakness of human understanding.

The works of God are but imperfectly known by us. We see their outside; or perhaps we discover fome of their qualities and relations, by obfervation and experiment affifted by reasoning: but even of the fimpleft of them we can give no definition that comprehends its real effence. It is justly obferved by Locke, that nominal effences only, which are the creatures of our own minds, are perfectly comprehended by us, or can be properly defined; and even of these there are many too fimple in their nature to admit of definition. When we cannot give precifion to our notions by a definition, we must endeavour to do it by attentive reflection upon them, by obferving minutely their agreements and differences, and efpecially by

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