The idea of man, for instance, makes part of the complex ideas of Peter and Paul, since it is equally to be found in both. There is no such thing as man in general. This partial idea has then no reality out of the mind, but it has one in the mind, where it exists separately from the aggregate or individual ideas of which it is a part. All our general ideas are then so many abstract ideas, and you see that we form them only in consequence of taking from each individual idea that which is common to all. ‘But what, in truth, is the reality which a general and abstract idea has in the mind. It is nothing but a name: or, if it is any thing more, it necessarily ceases to be abstract, and general. When, for example, I think of a _man_, I consider this word as a common denomination, in which case, it is very evident, that my idea is in some sort circumscribed within this name, that it does not extend to anything beyond it, and that consequently it is nothing but the name itself. If, on the contrary, thinking of man in general, I contemplate any thing in this word, besides the mere denomination, it can only be by representing myself to some one man; and a man can no more be man in general, or in the abstract in my mind, than in nature. Abstract ideas are therefore only denominations. If we will absolutely think that they are something else, we shall only resemble a painter who should obstinately persist in painting the figure of a man in general, and who would still paint only individuals. This observation concerning abstract and general ideas, demonstrates that their clearness depends entirely on the order in which we have arranged the denominations of classes; and that, consequently, to determine this sort of ideas, there is only one means, which is to construct a language properly. ‘This confirms what we have already demonstrated, how necessary words are to us: for if we had no general terms, we should have no abstract ideas, we should have neither _genera_, or _species_, and without _genera_ and _species_, we could reason upon nothing. But if we reason only by means of words this is a new proof that we can only reason well or ill, according as the language, in which we reason, is well or ill made. The analysis of our thoughts can only enable us to reason in proportion as by instructing us how to class our abstract ideas, it enables us how to form our language correctly, and the whole art of reasoning is thus reduced to the art of well speaking.’ What in this supremacy of words is to be the criterion of well speaking the Abbé does not say.