Since Nature (here meaning total reality and its processes) has not read very carefully the American Declaration of Independence or the French Revolutionary Declaration of the Rights of Man, we are all born unfree and unequal: subject to our physical and psychological heredity, and to the customs and traditions of our group; diversely endowed in health and strength, in mental capacity and qualities of character. Nature loves difference as the necessary material of selection and evolution; identical twins differ in a hundred ways, and no two peas are alike.
