of masses, not of points, a mere confused result of a number of impressions, not analysed by the mind, since there is no object which does not consist of an infinite number of parts, and we have not an infinite number of distinct ideas, answering to them. The knowledge of every finite being rests in generals, and if we think to exclude all generality from our ideas of things, as implying a want of perfect truth and clearness, it will be impossible for the mind to form an idea of any one object whatever. Let any person try the experiment of counting a flock of sheep driven fast by him, and he will soon find his imagination unable to keep pace with the rapid succession of objects, and his idea of a positive number slide into the general notion of multitude. But because there are more objects passing before him than he can possibly count, he will not, therefore, think that there are none, nor will the word, _flock_, present to his mind a mere name without any idea corresponding to it. Every act of the attention, every object we see or think of, offers a proof of the same kind. These remarks will be found to contain the answer to the common argument used on this subject, that in thinking of a man in general, we must always conceive of a man of a particular size and figure. Now if it be meant that when we pronounce the word _man_, we have either no idea at all, or a distinct and perfect one of an entire figure of a man with all its parts and proportions, it would amount to a knowledge, which no sculptor or painter ever had of any one figure of which he was the most thorough master, and which he had immediately before him. Or if it be only meant that we think of a particular height, which must be a precise, positive, determinate idea, even this supposition may in the same way be shewn to be exceedingly fallacious, and an inversion of the natural order of our ideas. For take any given height of a man, whether tall, short, or middle-sized, and let that height be as visible as you please, yet the actual height to which it amounts must be made up of the length of the different parts, the head, the face, the neck, the body, limbs, &c. all which must be distinctly added together by the mind, before the sum total which they compose can be pretended to be a precise, definite, individual idea. In the impression then of a given visible object, we have only a general idea of something more or less extended, and never of the precise length itself, for this precise length (as it is thought to be) is necessarily composed of a number of subordinate lengths, too many and too minute to be separately attended to, or jointly conceived by the mind, and at last loses itself in the infinite divisibility of matter. What sort of absolute certainty can therefore be found in any such image or ideas, I cannot well conceive: it seems to me like seeking for distinctness in the dancing of insects in the evening sun, or for fixedness and rest in the motion of the sea.