"Search deeply the facts in the comparison I have just made, you will see how in one part the organ which serves for acts of thought is perfected and acquires greater size and power, owing to sustained and varied exercise, especially if this exercise offers no more interruptions than are necessary to prevent the exhaustion of its powers; and, on the other hand, you will perceive how the circumstances which prevent an individual from exercising this organ, or from exercising it habitually only while considering a small number of objects which are always of the same nature, impede the development of his intellectual faculties. "After what I have just stated as to the results in man of a slight exercise of the organ by which he thinks, we shall no longer be astonished to see that in the nations which have come to be the most distinguished, because there is among them a small number of men who have been able, by observation and reflection, to create or advance the higher sciences, the multitude in these same nations have not been for all that exempted from the most absurd errors, and have not the less always been the dupe of impostors and victims of their prejudices. "Such is, in fact, the fatality attached to the destiny of man that, with the exception of a small number of individuals who live under favorable though special circumstances, the multitude, forced to continually busy itself with providing for its needs, remains permanently deprived of the knowledge which it should acquire; in general, exercises to a very slight extent the organ of its intelligence; preserves and propagates a multitude of prejudices which enslave it, and cannot be as happy as those who, guiding it, are themselves guided by reason and justice. "As to the animals, besides the fact that they in descending order have the brain less developed, they are otherwise proportionally more limited in the means of exercising and of varying their intellectual processes. They each exercise them only on a single or on some special points, on which they become more or less expert according to their species. And while their degree of organization remains the same and the nature of their needs (_besoins_) does not vary, they can never extend the scope of their intelligence, nor apply it to other objects than to those which are related to their ordinary needs. "Some among them, whose structure is a little more perfect than in others, have also greater means of varying and extending their intellectual faculties; but it is always within limits circumscribed by their necessities and habits.