Ethics » Meta ethics » Naturalism
Bentham was not satisfied to accept Hume's argument, however. He observed that "nature has placed mankind under two sovereign masters: the pursuit of pleasure and the avoidance of pain". For Bentham, who first coined the term "utilitarianism", it was simply a matter of common sense to judge that good actions produced "the greatest happiness for the greatest number" and that bad actions produced pain.
Utilitarianism is one remedy against the problems with ethical language, though arguably it is just as difficult to define and measure pleasure and pain as it is to define and measure a broader concept of goodness. Nevertheless, utilitarianism had an air of scientific credibility and survives as a major school of ethics and one enduringly popular with politicians, lawyers and scientists for its ability to provide apparently verifiable data to support claims such as "murder is wrong".
Limitations of utilitarianism
However even from the earliest days utilitarianism has attracted harsh criticism. John Stuart Mill, Bentham's godson, argued that Bentham's understanding of pleasure was deficient and that the whole system was beset by the problem of prediction, that is, of accurately predicting the outcomes of actions, and of being influenced by self-interest. Immanuel Kant would have agreed with much of Mill's argument.
Kant's own approach to ethics rejected the simplistic notion that we are driven by raw pleasure and the avoidance of pain, as much as it rejected the traditional prescriptive definition of human nature and flourishing that had been handed down from Aristotle and the Church. Instead he argued that human nature lies in being rational and free and that we flourish when we act on principle and freely for principle's sake consistently.
Immanuel Kant's definition of human nature and goodness gets us no further towards a defence of the meaningfulness of statements relating to good, bad, right and wrong. There is no scientific tool to measure the rationality of the maxim of somebody's action, nor to measure the freedom or motivation of their will when they determined on the action. Kant claims that there is a single rational principle behind all good actions and that, though this principle would be known synthetically from experience, the goodness of maxims would be known analytically, by their logical relationship with the single categorical imperative.