There is one common account which can perhaps be disposed of here; the view that other-regarding behavior is motivated by a desire to avoid the guilt feelings which would result from selfish behavior. Guilt cannot provide the basic reason, because guilt is precisely the pained recognition that one is acting or has acted contrary to a reason which the claims, rights, or interests of others provide- a reason which therefore must be antecedently acknowledged.
Thomas Nagel, The Possibility of Altruism, p. 80 (footnote #1).