Fragments of the Early Stoics, Volume 3: Chrysippus (Ethics)

...the community with the human race, charity, friendship, justice, and the remaining virtues; none of which can exist unless it is gratuitous. For that which is driven to duty by pleasure as if by some wage, that is not virtue, but a deceptive imitation and simulation of virtue.

22 Cicero, On Ends II 14, 44. Thus, with the opinions of others removed, there remains a struggle not for me with Torquatus, but for virtue with pleasure. This struggle, indeed, an acute and diligent man, Chrysippus, does not despise; and he thinks the whole distinction of the highest good is placed in their comparison.

23 Plutarch, On Stoic Self-Contradictions ch. 15 p. 1040c. Again, in his works On Justice, having hinted that it is possible for those who posit pleasure as a good but not as an end to still preserve justice, he has said this word for word: "For perhaps, with pleasure being left as a good but not an end, and with the honorable being among the things choiceworthy for their own sake, we might preserve justice, leaving the honorable and the just as a greater good than pleasure." Cf. ch. 13, where the same words clearly exist.
Plutarch, On Common Conceptions ch. 25 p. 1070d. In his works On Justice, if someone were to hypothesize pleasure as the end, he does not think justice can be preserved; but if not as an end but simply as a good, he thinks it can. I do not think you need to hear me reciting the words now; for the third book On Justice can be obtained from anywhere.

24 Plutarch, On Stoic Self-Contradictions ch. 15 p. 1040e. But so that he does not leave any excuse for contradictions, writing against Aristotle on justice, he says "that he does not speak correctly, that if pleasure is the end, justice is abolished, and with justice, each of the other virtues is also abolished. For while justice is truly abolished by them, nothing prevents the other virtues from existing, even if they are not choiceworthy for their own sake, they will still be good and virtues." Then he addresses each one by name. It is better to take up his actual words: "For with pleasure appearing as the end according to such a view, all such things do not seem to me to be included. Therefore, it must be said that neither is any one of the virtues choiceworthy for its own sake, nor are the vices to be avoided, but all these things must be referred to the underlying target. However, according to them, nothing will prevent courage, prudence, temperance, endurance, and virtues similar to these from being among the goods, and the opposite from being to be avoided."

25 Plutarch, On Common Conceptions ch. 25 p. 1070d. And indeed, that of two goods, the one being the end and the other being toward the end, the end is greater and more perfect, is ignored by no one. Chrysippus also knows the difference, as is clear in his third book On Goods; for he disagrees with those who consider knowledge to be the end.