I must ask the reader to distinguish carefully the question discussed in this chapter, which relates to the objects of desires and aversions, from the different question whether the causes of these impulses are always to be found in antecedent experiences of pleasure and pain. The bearing of this latter question on Ethics, though not unimportant, is manifestly more indirect than that of the question here dealt with: and it will be convenient to postpone it till a later stage of the discussion, Cf. post, Book ii. chap. vi, §2, and Book iv. chap. iv. §1.