The luminous undulations which thus radiate through the brain are not homogeneous as regards their ex trinsic characters, and do not equally affect the different regions of the cortex in which they are distributed. Thus, not only do they transmit to the sensorium per ceptions of the different gradations of intensity of light, but furnish as well the most specific notions of the colour of surrounding objects. There are thus, in fact, two different modes in which the elements of the sen sorium may be affected and in most men one or other of these modes usually predominates. We meet with certain organizations which from this point of view are very unequally endowed. Every one knows that if all persons with the gift of sight have the faculty of being impressed by light, all have not the faculty of perceiv ing colours in an equal degree, and that their are persons who suffer from a peculiar form of blindness which makes certain hues virtually non-existent for them.* We all know that certain painters, who are gifted in the highest degree with that natural aptitude for perceiving in a complete manner the different grada tions of the colour of objects, can give to their works a quite unique intensity of colour, a richness of tone which they draw from their own personality, and which their less gifted rivals can neither comprehend nor Optic impressions, as well as sensitive, are divided into two contingents which are separately distributed, either in the sphere of psychical or the sphere of intel lectual activity.
i. Genesis of the Notion of Beauty and Ugliness.
The particular contingent of optic impressions des tined to be distributed in the sphere of psychical activity appears to be the origin of that faculty by which we pronounce as to the beauty or ugliness of the thing that impresses us, and in this it resembles sensitive im pressions that furnish us with the 'notion of happiness, by means of a regularly accomplished physiological process. These optic impressions are similarly the fun damental impressions that engender in us the notion of the beautiful.
These optic impressions, indeed, originating as they do, like those of general sensibility, in the peripheral regions, do not ascend into the sensorium in the condi tion of atonic, indifferent, slightly-stimulating impres sions. They carry with them the special condition into which the peripheral plexuses have been thrown at the moment of their genesis, and the simultaneous notions of concomitant pleasure or pain. When an agreeable spectacle presents itself to our eyes, our retinas, being impressionable nervous plexuses, are more or less directly gratified as regards their natural sensibility, just as when an agreeable sensation affects our sensitive nerves ; and this special satisfaction is transmitted to the sensorium, thereby producing in it also a special vital condition, a new state which we express under the denomination of a sensation of beauty.*
Tip; subjective notion that we have of the beauty of things is thus, in the primitive man, who knows nothing of either the subtleties of art, or the casuistries of the different schools, or the code of amateurs, fundamen tally connected with the memory of an agreeable impression, a purely visual satisfaction felt by the retina when agreeably affected.
Children love all that is brilliant and that glitters in the sun ; the inhabitants of northern countries and cer tain savage tribes, are attracted by the sight of objects of a vivid colour, and tints which violently affect the sight. These are the rudimentary forms of the idea of the beautiful, which is really derived from a primitive physical impression. It is only by degrees, by means of the participation of the intellect, the culture of the judgment, and comparison, that this first notion comes to perfection in us, and becomes a rational well-digested appreciation, though having its origin in a physical impression which is at first addressed to our optic sensibility.
Conversely we can comprehend that those things which produce on the retina a painful impression, which are unpleasant to see, are also those which produce a pain ful impression on the sensorium, and which bring with them a notion the reverse of the former, that is to say that of ugliness.
2. Optic impressions, when carried up to the senso rium, not only excite in it special conditions by means of which the notion of beauty or ugliness is naturally developed in us, but they are further gifted with a more intense penetrative power, and while taking upon them a thousand forms they touch and set vibrating all the chords of our emotivity.
Thus the sight of a landscape in full sunshine, enamelled with flowers of a thousand hues, and covered with green meadows with distant horizons, develops in us sentiments of satisfaction which gratify our sensibility and cause it to expand ; while a gloomy place, shut in by high walls, and without verdure, sad dens the sensorium, and develops in us a very legitimate sentiment of repulsion, in which all share. Thus these sentiments of attraction and repulsion are directly imposed upon us in consequence of the perceived impression, without the intervention of memory or of old reminiscences.
By reason of those mysterious affinities which unite the present with the past, as regards our ideas and emotions, a simple appearance, a simple optic impres sion, is capable of reviving old memories, and according to circumstances, of setting in vibration all the different emotional chords that it touches within us.