Hence where colours are required to be distinct, those which are opposite to each other, should be brought into succession or vicinity; as red and green, orange and blue, yellow and violet; but where colours are required to intermix imperceptibly, or slide into each other, these should not be chosen; as they might by contrast appear too glaring or tawdry. These gradations and contrasts of colours have been practically employed both by the painters of landscape, and by the planters of ornamental gardens; though the theory of this part of the pleasure derived from visible objects was not explained before the publication of the paper on ocular spectra above mentioned; which is reprinted at the end of the first part of Zoonomia, and has thrown great light on the actions of the nerves of sense in consequence of the stimulus of external bodies.
IV. Association of agreeable sentiments with visible objects.
Besides the pleasure experienced simply by the perception of visible objects, it has been already shown, that there is an additional pleasure arising from the inspection of those, which possess novelty, or some degree of it; a second additional pleasure from those, which possess in some degree a repetition of their parts; and a third from those, which possess a succession of particular colours, which either contrast or slide into each other, and which we have termed melody of colours.
We now step forward to the fourth source of the pleasures arising from the contemplation of visible objects besides that simply of perception, which consists in our previous association of some agreeable sentiment with certain forms or combinations of them. These four kinds of pleasure singly or in combination constitute what is generally understood by the word Taste in respect to the visible world; and by parity of reasoning it is probable, that the pleasurable ideas received by the other senses, or which are associated with language, may be traced to similar sources.
It has been shown by Bishop Berkeley in his ingenious essay on vision, that the eye only acquaints us with the perception of light and colours; and that our idea of the solidity of the bodies, which reflect them, is learnt by the organ of touch: he therefore calls our vision the language of touch, observing that certain gradations of the shades of colour, by our previous experience of having examined similar bodies by our hands or lips, suggest our ideas of solidity, and of the forms of solid bodies; as when we view a tree, it would otherwise appear to us a flat green surface, but by association of ideas we know it to be a cylindrical stem with round branches. This association of the ideas acquired by the sense of touch with those of vision, we do not allude to in the following observations, but to the agreeable trains or tribes of ideas and sentiments connected with certain kinds of visible objects.
V. Sentiment of Beauty.
Of these catenations of sentiments with visible objects, the first is the sentiment of Beauty or Loveliness; which is suggested by easy-flowing curvatures of surface, with smoothness; as is so well illustrated in Mr. Burke's Essay on the Sublime and Beautiful, and in Mr. Hogarth's analysis of Beauty; a new edition of which is much wanted separate from his other works.
The sentiment of Beauty appears to be attached from our cradles to the easy curvatures of lines, and smooth surfaces of visible objects, and to have been derived from the form of the female bosom; as spoken of in Zoonomia, Vol. I. Section XVI. on Instinct.
Sentimental love, as distinguished from the animal passion of that name, with which it is frequently accompanied, consists in the desire or sensation of beholding, embracing, and saluting, a beautiful object.
The characteristic of beauty therefore is that it is the object of love; and though many other objects are in common language called beautiful, yet they are only called so metaphorically, and ought to be termed agreeable. A Grecian temple may give us the pleasurable idea of sublimity; a Gothic temple may give us the pleasurable idea of variety; and a modern house the pleasurable idea of utility; music and poetry may inspire our love by association of ideas; but none of these, except metaphorically, can be termed beautiful; as we have no wish to embrace or salute them.