It is then the glandular, then the nutritive system which enjoy a marked superiority in the state of their vital powers. Lastly, when these powers have been successively developed, over all the system, they return to the organs of the animal life, the senses resume their activity, the functions of the brain their energy, the muscles their vigour. Whoever reflects upon what he has experienced after a somewhat copious repast, will be easily convinced of the truth of these remarks. In this way, the whole of the functions represent a species of circle, of which the one half belongs to the organic, the other to the animal life, the vital powers seem successively to traverse these two halves. When they are found in one half, the other is proportionably deprived of them, nearly in the same manner as every thing appears to languish and be reanimated in the two portions of the globe, accordingly as the sun refuses, or sheds down his beneficent influence. Should any farther proof be required of this inequality of distribution with regard to the vital powers, we may find it in the process of nutrition. This process has always an excess of action in some one of the organs, which at such time may be said to live more than the others do. In the fœtus, the brain and the nerves, the inferior members after birth, and at the age of puberty, the genital parts and breast appear to grow at the expense of the others. From such a variety of considerations, we may establish the following to be a fundamental law of the distribution of the vital powers, namely, that when they increase in one part, they decrease in the rest of the living œconomy, that the sum of them can never be augmented, and that they only transfer themselves successively from one organ to another. By the help of these general data, it is easy to perceive why we cannot at the same time attain to perfection in the various parts of our animal life, why we cannot at the same time excel in all the sciences. Universality of knowledge in the same individual is a chimera; it is repugnant to the laws of our organization, and if history afford us some few instances of extraordinary men, who have thrown an equal light upon many of the sciences, such instances are but so many exceptions to the common laws of nature; for who are we, that we should venture on the pursuit of many things at once, and hope to attain in all of them a perfection, which for the most part, even when we have but a single object in view, escapes us? Were we capable of following at once a number of occupations, such occupations would be those which have the greatest analogy among themselves with respect to the organs which they bring into exercise: and by restraining ourselves in this way within a narrow circle, we may, indeed, with a greater degree of facility excel in many parts; but even here the great secret of being superior in any one of them, is that of possessing but a mediocrity in the others.