'Tis universally allowed, that the capacity of the mind is limited, and can never attain a full and adequate conception of infinity: and though it were not allowed, 'twould be sufficiently evident from the plainest observation and experience. 'Tis also obvious, that whatever is capable of being divided _in infinitum_, must consist of an infinite number of parts, and that 'tis impossible to set any bounds to the number of parts without setting bounds at the same time to the division. It requires scarce any induction to conclude from hence, that the _idea_, which we form of any finite quality, is not infinitely divisible, but that by proper distinctions and separations we may run up this idea to inferior ones, which will be perfectly simple and indivisible. In rejecting the infinite capacity of the mind, we suppose it may arrive at an end in the division of its ideas; nor are there any possible means of evading the evidence of this conclusion. 'Tis therefore certain, that the imagination reaches a _minimum_, and may raise up to itself an idea, of which it cannot conceive any subdivision, and which cannot be diminished without a total annihilation. When you tell me of the thousandth and ten thousandth part of a grain of sand, I have a distinct idea of these numbers and of their different proportions; but the images which I form in my mind to represent the things themselves, are nothing different from each other, nor inferior to that image, by which I represent the grain of sand itself, which is supposed so vastly to exceed them. What consists of parts is distinguishable into them, and what is distinguishable is separable. But, whatever we may imagine of the thing, the idea of a grain of sand is not distinguishable nor separable into twenty, much less into a thousand, ten thousand, or an infinite number of different ideas. 'Tis the same case with the impressions of the senses as with the ideas of the imagination. Put a spot of ink upon paper, fix your eye upon that spot, and retire to such a distance that at last you lose sight of it; 'tis plain, that the moment before it vanished, the image, or impression, was perfectly indivisible. 'Tis not for want of rays of light striking on our eyes, that the minute parts of distant bodies convey not any sensible impression; but because they are removed beyond that distance, at which their impressions were reduced to a _minimum_, and were incapable of any farther diminution. A microscope or telescope, which renders them visible, produces not any new rays of light, but only spreads those which always flowed from them; and, by that means, both gives parts to impressions, which to the naked eye appear simple and uncompounded, and advances to a _minimum_ what was formerly imperceptible.