It is easy to perceive that it is in these successive changes in the constitution of man that we must look for the origin of those differences which now distinguish men, who, it is allowed, are as equal among themselves as were the animals of every kind, before physical causes had introduced those varieties which are now observable among some of them. It is, in fact, not to be conceived that these primary changes, however they may have arisen, could have altered, all at once and in the same manner, every individual of the species. It is natural to think that, while the condition of some of them grew better or worse, and they were acquiring various good or bad qualities not inherent in their nature, there were others who continued a longer time in their original condition. Such was doubtless the first source of the inequality of mankind, which it is much easier to point out thus in general terms, than to assign with precision to its actual causes. Let not my readers therefore imagine that I flatter myself with having seen what it appears to me so difficult to discover. I have here entered upon certain arguments, and risked some conjectures, less in the hope of solving the difficulty, than with a view to throwing some light upon it, and reducing the question to its proper form. Others may easily proceed farther on the same road, and yet no one find it very easy to get to the end. For it is by no means a light undertaking to distinguish properly between what is original and what is artificial in the actual nature of man, or to form a true idea of a state which no longer exists, perhaps never did exist, and probably never will exist; and of which, it is, nevertheless, necessary to have true ideas, in order to form a proper judgment of our present state. It requires, indeed, more philosophy than can be imagined to enable any one to determine exactly what precautions he ought to take, in order to make solid observations on this subject; and it appears to me that a good solution of the following problem would be not unworthy of the Aristotles and Plinys of the present age. _What experiments would have to be made, to discover the natural man? And how are those experiments to be made in a state of society_? So far am I from undertaking to solve this problem, that I think I have sufficiently, considered the subject, to venture to declare beforehand that our greatest philosophers would not be too good to direct such experiments, and our most powerful sovereigns to make them. Such a combination we have very little reason to expect, especially attended with the perseverance, or rather succession of intelligence and good-will necessary on both sides to success.