This article argues that the idea of conscience can play a useful, albeit limited and highly general, explanatory role in private law, if we have regard to two distinctive contexts in which it is used. First, it tells us something about how equitable obligations arise and reminds us that they directly enforce moral duties. Second, it conveys the message that the courts are reluctant to impose primary liabilities which restrict the exercise of legal rights absent a past or prospective breach of moral duty by the defendant. Without further explanation, the indiscriminate invocation of conscience in both contexts can lead to confusion and uncertainty, but if the distinction between obligation and liability is observed, the explanatory force of conscience in relation to each becomes clearer, and it plays a valuable role in bolstering the authority of private law.