Locke's Essay Concerning Human Understandings, largely composed in exile in the mid-1680s and published in 1689, declared in expanding upon his 1676 journal account that ‘Nature’ had put into men ‘a desire of Happiness, and an aversion to Misery’. These were innate ‘practical principles’ which influenced ‘all our Actions, without ceasing’. According to the Essay ‘That we call good’ was what was ‘apt to cause or increase pleasure, or diminish Pain in us; or else to procure, or preserve us the possession of any other Good, or absence of any Evil’. Men were obliged, physiologically and morally, to pursue their own happiness.

The Essay simultaneously assaulted innate ideas. For almost all of Locke's English contemporaries, Anglicans or dissenters, such innate ideas informed men that they had to serve others and provided an influence of conscience to help to bring them to practise that duty. While accepting significant elements of Locke's empiricism, many eighteenth-century philosophers, including Locke's own pupil, the third earl of Shaftesbury, were to develop an account of men's minds that described a natural ‘sympathy’ or ‘benevolence’ towards other men. Locke's analysis of the mind left no room for such an account and was criticised by these philosophers because they thought that it was difficult on Locke's premisses to provide a basis for an ethic of mutual service, or even for the lesser mutual concern necessary to establish justice.