Philosopher and English Economist, Chief Representative of the utilitarian positivism, born in London in 1806 and died in Avignonel on May 8, 1873. Son of James Mill, became interested in the natural sciences, law, politics, economics and philosophy. His most important work is A System of Logic, Ratiocinative and Inductive (2 vols., 1843). He received the influence of Hume and other British empiricists (see empiricism), but also of French positivism.
As empiricist, his theory of knowledge relies on the associative psychology. Given that all knowledge comes from experience, the scientific rigour must aim at the constant observation of the empirical fact. The method will be the inductive: the observation of natural facts, through the connection of phenomena, we come to the knowledge of the laws by which they are governed. What, at first, is to find causal relationships between the observed phenomena; i.e. that observation in a data set one can conclude a causal generalization. For this, you need to find a system that allows you to differentiate accidental generalizations (that a mere coincidence) "nomicas" calls (from the Greek nomos, "law"); These latest are which express relations between events that are not the result of chance and, therefore, which allow to formulate by induction the laws of nature. However, the principle of induction allows to generalize any information from observations, without distinguishing whether the generalization is nomic or accidental. For this reason, as he had previously done Francis Bacon to formulate his famous "tables", John Stuart Mill designed a procedure allowing to establish without any doubt that distinction between "causal" and "casual". It's four rules, or "canons", designed to find causal relationships from repeated observations of phenomena, and they are as follows:
1st canon of concordance: from data collection looking at repeated associations of the phenomenon "A" and the "a" phenomenon, i.e., if that ever occurs also presents "A", "a", we can conclude that it is likely that "A" is the cause of "a". This canon is based on the enumerated inducccion, but also makes use of the revulsive, by making it possible to rule out possible hypotheses: those in which cases do not match. However, the concordance itself Canyon alone is not conclusive, since there may be multiple causes for a same effect; What establishes this canon is that "A" is cause or part of the cause of "a", i.e., "A" is sufficient condition, but not necessary, "a". Establish the need for the law requires application of the following canon.
2nd Canyon of difference: it's check not only that whenever it happens "A" happening "to", but that the absence of "a" corresponds consistently with the absence of "A". This allows to prove not only that the cause is sufficient effect condition, but also that the effect is a necessary condition of the cause. Eliminator shed is much more evident in this second canon, which must be complemented with the agreement to ensure that the resulting generalization is nomic.
The other two guns can be considered auxiliary of these two main.
3rd canon of concomitant variations: ensures the causal relationship to note that an increase of grade in the "A" cause causes an increase in grade "a" indeed. Refers therefore this canon to the intensity with which they are cause and effect.
4th canon of waste: allows to establish causal generalizations between more than one cause and more of one effect, but it is the more auxiliary of the four cannons, since it assumes prior knowledge of the causal relationship.
Mill is also worried about ethics. Under the influence of J. Bentham, advocated the hedonistic utilitarianism: is good which is useful. Since every man seeks pleasure and happiness, ethics should aim to provide the greatest happiness to the greatest number of people possible. Ethics of utilitarian Court is not, therefore, a simple defense of selfishness. Policy declares open defender of liberalism, and supports the vote of women and social promotion along with the defence of their rights.