Welfare theories based on the ethics of motive
The ethics of motive aims to establish the motives - the causes - of human conduct. It is an ancient conception which dates back to
Aristippus and Epicurus. In some of its expressions, the motive of human conduct is desire or will to survive; in others, it is the search for pleasure. Lorenzo Valla, Baruch Spinoza, John Locke, Gottfried Leibniz, David Hume, Cesare Beccaria, Jeremy Bentham, Immanuel Kant and Bertrand Russell espouse this ethical doctrine. Good is intended in the subjective sense, and it is perfection because it is desired. Establishing which is the most rational of alternative goods is meaningless, unless they are intermediate ends for reaching a superior good. More specifically, a thing is useful when it is desired as a means or is a means to attain pleasure; while when a thing is liked or desired for itself, it is good in itself (subjective intrinsic value). In both cases, the reference is always to subjective desire or pleasure. By identifying with pleasure or preference the motive that leads human beings to act, moral good is an object of desire (a natural object), and ethics is simply a discipline of conduct, or the science that guides human choices to the end of pleasure or in order to satisfy preferences.
Hedonism (egoism and utilitarianism) and the neo-Humean view are ethics of motive (see ss. 12.2.1 and 12.2.2 below). They are the ethical foundations of different economic welfare models. For our purpose, we focus on: i) the theory of social utility, which is 'the accidental deposit of the historical association between English Economics and Utilitarianism' (Robbins, 1984, p.141); ii) the new welfare economics (NWE) and the theory of social choice (TSC) which are instead based on the neo-Humean view; and iii) rule utilitarianism (RU), which is the result of a combination of assumptions associated with utilitarianism and the neo-Humean view.