It is not easy to explain this phenomenon without recurring to organic causes, which, on determinate occasions, produce the same effect upon the soul, as the impressions of the external senses. It is certain that the internal representation reaches, in certain cases, so high a point of vividness, that the subject confounds it with the impressions of the senses. This can only be explained by saying that the interior organic affection has become so powerful, as to be equivalent to that which the impression of an object operating upon the external organ, could have caused. 121. In this spontaneous production it is to be remarked that present representations do not always correspond with others previously received; but a power of combination is developed in them from which result imaginary objects entirely new. This combination is sometimes exercised in a perfectly blind manner, and then follow extravagant results; but, at other times, this activity subjected to certain conditions produces, independently of free will, objects artistically beautiful and sublime. Genius is nothing else than the spontaneity of the imagination and sentiment, developed in subordination to the conditions of the beautiful. Artists, not gifted with genius, do not lack strength of will to produce works of genius; nor are they wanting in imagination to reproduce a beautiful object if they have once seen it; they do not lack discernment and taste to distinguish and admire beautiful objects, nor are they ignorant of the rules of art or of all that can be said to explain the character of beauty; what they lack is that instinctively fine spontaneity which develops itself in the most recondite sinuosities of the soul, and far from being dependent upon the free will of its possessor, directs and domineers over him, pursues him in sleep as in the hours of waking, in the time of recreation as in that of business, and often consumes the very existence of the privileged man, as a furious fire bursts the sides of the frail cage that holds it. 122. Free production occurs when representations are offered to us by command of our will, and under the conditions it prescribes, as in works of art, and in the combinations of those figures which constitute the object of the science of geometry. 123. This _a priori_ construction cannot be referred to a type existing in our imagination; since, as this type would then be the sensible representation itself, it would not need to be constructed. How then is it possible to form a representation of which we have not already the image? It is not enough to possess the elements, that is, figurable extension, since with them infinite figures may be constructed; something else then is needed, something to serve as a rule, in order that the desired representation may result.