Thus, amongst the blades of grass or leaves of the same tree, though no two can be found exactly alike, yet the general form is invariable:  a naturalist, before he chose one as a sample, would examine many, since, if he took the first that occurred, it might have, by accident or otherwise, such a form as that it would scarcely be known to belong to that species; he selects, as the painter does, the most beautiful, that is, the most general form of nature.

Every species of the animal, as well as the vegetable creation, may be said to have a fixed or determinate form towards which nature is continually inclining, like various lines terminating in the centre; or it may be compared to pendulums vibrating in different directions over one central point; and as they all cross the centre, though only one passes through any other point, so it will be found that perfect beauty is oftener produced by nature than deformity; I do not mean than deformity in general, but than any one kind of deformity.  To instance in a particular part of a feature:  the line that forms the ridge of the nose is beautiful when it is straight; this then is the central form, which is oftener found than either concave, convex or any other irregular form that shall be proposed.  As we are then more accustomed to beauty than deformity, we may conclude that to be the reason why we approve and admire it, as we approve and admire customs and fashions of dress for no other reason than that we are used to them; so that, though habit and custom cannot be said to be the cause of beauty, it is certainly the cause of our liking it; and I have no doubt but that, if we were more used to deformity than beauty, deformity would then lose the idea now annexed to it, and take that of beauty; as, if the whole world should agree that yes and no should change their meanings, yes would then deny, and no would affirm.

Whoever undertakes to proceed further in this argument, and endeavours to fix a general criterion of beauty respecting different species, or to show why one species is more beautiful than another, it will be required from him first to prove that one species is really more beautiful than another.  That we prefer one to the other, and with very good reason, will be readily granted; but it does not follow from thence that we think it a more beautiful form; for we have no criterion of form by which to determine our judgment.  He who says a swan is more beautiful than a dove, means little more than that he has more pleasure in seeing a swan than a dove, either from the stateliness of its motions, or its being a more rare bird; and he who gives the preference to the dove, does it from some association of ideas of innocence that he always annexes to the dove; but, if he pretends to defend the preference he gives to one or the other by endeavouring to prove that this more beautiful form proceeds from a particular gradation of magnitude, undulation of