"It is useless to ask what is the source of natural inequality, because that question is answered by the simple definition of the word. Again, it is still more useless to inquire whether there is any essential connection between the two inequalities; for this would be only asking, in other words, whether those who command are necessarily better than those who obey, and if strength of body or of mind, wisdom or virtue are always found in particular individuals, in proportion to their power or wealth: a question fit perhaps to be discussed by slaves in the hearing of their masters, but highly unbecoming to reasonable and free men in search of the truth." -- Jean Jacques Rousseau, A Dissertation on the Origin and Foundation of the Inequality of Mankind (Trans. by G. D. H. Cole)Of course, CEOs cannot receive their pay except through services provided to them by a society existing beforehand:
"The difference of natural talents in different men is, in reality, much less than we are aware of; and the very different genius which appears to distinguish men of different professions, when grown up to maturity, is not upon many occasions so much the cause, as the effect of the division of labour. The difference between the most dissimilar characters, between a philosopher and a common street porter, for example, seems to arise not so much from nature, as from habit, custom, and education. When they came into the world, and for the first six or eight years of their existence, they were, perhaps, very much alike, and neither their parents nor playfellows could perceive any remarkable difference. About that age, or soon after, they come to be employed in very different occupations. The difference of talents comes then to be taken notice of, and widens by degrees, till at last the vanity of the philosopher is willing to acknowledge scarce any resemblance. But without the disposition to truck, barter, and exchange, every man must have procured to himself every necessary and conveniency of life which he wanted. All must have had the same duties to perform, and the same work to do, and there could have been no such difference of employment as could alone give occasion to any great difference of talents.
As it is this disposition which forms that difference of talents, so remarkable among men of different professions, so it is this same disposition which renders that difference useful. Many tribes of animals acknowledged to be all of the same species, derive from nature a much more remarkable distinction of genious, than what, antecedent to custom and education, appears to take place among men. By nature a philosopher is not in genius and disposition half so different from a porter, as a mastiff is from a greyhound, or a greyhound from a spaniel, or this last from a shepherd's dog." -- Adam Smith, Wealth of Nations