Ideas of Modes.
First, MODES I call such complex ideas which, however compounded, contain not in them the supposition of subsisting by themselves, but are considered as dependences on, or affections of substances;--such as are the ideas signified by the words triangle, gratitude, murder, &c.

And if in this I use the word mode in somewhat a different sense from its ordinary signification, I beg pardon; it being unavoidable in discourses, differing from the ordinary received notions, either to make new words, or to use old words in somewhat a new signification; the later whereof, in our present case, is perhaps the more tolerable of the two.
5.

Simple and mixed Modes of Ideas.
Of these MODES, there are two sorts which deserve distinct consideration:-- First, there are some which are only variations, or different combinations of the same simple idea, without the mixture of any other;--as a dozen, or score; which are nothing but the ideas of so many distinct units added together, and these I call SIMPLE MODES as being contained within the bounds of one simple idea.
Secondly, there are others compounded of simple ideas of several kinds, put together to make one complex one;--v.g.

beauty, consisting of a certain composition of colour and figure, causing delight to the beholder; theft, which being the concealed change of the possession of anything, without the consent of the proprietor, contains, as is visible, a combination of several ideas of several kinds: and these I call MIXED MODES.
6.

Ideas of Substances, single or collective.
Secondly, the ideas of SUBSTANCES are such combinations of simple ideas as are taken to represent distinct PARTICULAR things subsisting by themselves; in which the supposed or confused idea of substance, such as it is, is always the first and chief.