The nature of the good: the ideal as a state of mind
In Britain at the beginning of the twentieth century, Moore's conception of the good as ideal had an important influence on ethics and on the theory of moral value. Moore's ethical conception is an important criticism of ethical naturalism or psychologism, from which modern ethics has profited. Moore calls naturalistic both hedonism and neo-Humean ethics, since they identify a property of a thing with the thing itself. Moore describes, as an example, two different kinds of philosopher: the hedonist who claims that 'good is pleasure' and the philosopher who states that 'good is what is desired'. 'Each of these will argue eagerly to prove that the other is wrong' (Moore, 1959 , pp. 10-11). Nevertheless, their position is merely a psychological one, since 'desire is something which occurs in our minds, and pleasure is something else which so occurs' (Moore, 1959 , pp. 10-11). In his Principia Ethica Moore defines ethics as the theory of the good in general. Ethical reasoning concerns two fundamental points: (a) the nature of the good in general (what is good and what is bad), and (b) the nature of good conduct (what good conduct is). In this section we consider the first point, in section 12.5 the second.
As for the nature of the good, Moore believes that 'our knowledge cannot be confined to the things which we can touch and see and feel' (1959 , p. 110). Indeed, when we say that a thing is good in itself, its goodness is an object of thought, a state of mind. To the question 'How can the good be defined?', his reply is that it cannot be defined and analysed since it is a 'quality which we assert to belong to a thing'. A 'definition states what are the parts which invariably compose a certain whole; and in this sense "good" has no definition because it is simple and has no parts' (1959 , p. 9). Each agent is intuitively aware of what good is, because nothing can prove the proposition that claims that the goodness of a thing is true. In other terms, each decision about what is good depends on a direct intuition in each specific case. Nevertheless, intuition - as an original and independent source of knowledge, or immediate knowledge of a truth - is not an alternative to reason, because 'nothing whatever can take the place of reasons for the truth of any proposition: intuition can only furnish a reason for holding any proposition to be true' (1959 , pp. 6-10, p. 144).
The identification of what is good is a complex issue, because we do not always approve of what we like, and there is no doubt that common sense believes that many less pleasant states of mind, are better than many others that are more pleasant. By admitting that the ends of human conduct derive from the rational and metaphysical nature of human beings, Moore defines the ideal as what is good in itself to a high degree. Life, nature, virtue, knowledge, truth, personal affections, beauty and justice may be good as ends in themselves.
The ideal (supreme good) has the characteristics of a complex organic whole. A thing may be judged to be good in different degrees: it may have intrinsic value, it may be bad, and it may be indifferent. According to Moore,
a thing belonging to any of these three classes may occur as part of a whole, which includes among its other parts other things belonging both to the same and to the other two classes; and these wholes, as such, may also have intrinsic value. The paradox, to which it is necessary to call attention, is that the value of such a whole bears no regular proportion to the sum of the values of its parts.
(1959 , p. 27; emphasis in original)
Therefore, it is a mistake of the doctrines based on methodological individualism to maintain that, if a certain number of things form a whole, the value of that whole is the sum of the value of things that compose it.
Nevertheless, even if Moore provides the principles of ethical reasoning and some conclusions about what is good, his ethics is not a complete system. Though he highlights that there is a contradiction in terms in the transition from egoism to utilitarianism that cannot be solved by assuming that the same conduct produces both these things, he does not provide a solution to the problem that private good and public good may not coincide (Skidelsky, 1983). In addition, he does not specifically admit any logical nexus between economic welfare and ethical good. Therefore, since a welfare theory requires a solution to these two problems, we focus on Keynes's thinking about social welfare, which tries to reconcile private interest and social good, and to justify the belief that there is no logical nexus between material welfare and ethical goodness.