Js Mill Sistema De Logica Sobre Comparacion

CHAPTER VII: Of Observation and Experiment - John Stuart Mill, The Collected Works of John Stuart Mill, Volume VII - A System of Logic Ratiocinative and Inductive [1843]

Edition used:

The Collected Works of John Stuart Mill, Volume VII - A System of Logic Ratiocinative and Inductive, Being a Connected View of the Principles of Evidence and the Methods of Scientific Investigation (BooksI-III), ed. John M. Robson, Introduction by RF McRae (Toronto: University of Toronto Press, London: Routledge and Kegan Paul, 1974).
CHAPTER III
Of the Ground of Induction

§ 1. [ Axiom of the uniformity of the course of nature ] Induction properly so called, as distinguished from those mental operations, sometimes though improperly designated by the name, which I have attempted in the precedingchapter to characterize, may, then, be summarily defined as Generalization from Experience. It consists in inferring from some individual instances in which a phenomenon is observed to occur, that it occurs in all instances of a certain class; namely, in all which resemble the former, in what are regarded as the material circumstances.
In what way the material circumstances are to be distinguishedfrom those which are immaterial, or why some of the circumstances are material and others not so, we are not yet ready to point out. We must first observe, that there is a principle implied in the very statement of what Induction is; an assumption with regard to the course of nature and the order of the universe; namely, that there are such things in nature as parallel cases; that what happensonce, will, under a sufficient degree of similarity of circumstances, happen again, and not only again, but a as often as the same circumstances recur a . This, I say, is an assumption, involved in every case of induction. And, if we consult the actual course of nature, we find that the assumption is warranted b. The universe, c so far as known to us c , is so constituted, that whatever is true inany one case, is true in all cases of a certain description; the only difficulty is, to find what description.
This universal fact, which is our warrant for all d inferences d from experience, has been described by different philosophers in different forms of language: that the course of nature is uniform; that the universe is governed by general laws; and the like. One of the most usual of thesemodes of expression, but also one of the most inadequate, is that which has been brought into familiar use by the metaphysicians of the school of Reid and Stewart. The disposition of the human mind to generalize from experience,—a propensity considered by these philosophers as an instinct of our nature,—they usually describe under e some such name as e “our intuitive conviction that the futurewill resemble the past.” Now it has been well pointed out f by Mr. Bailey * that f (whether the tendency be or not an original and ultimate element of our nature), Time, in its modifications of past, present, and future, has no concern either with the belief itself, or with the grounds of it. We believe that fire will burn to-morrow, because it burned to-day and yesterday; but we believe, onprecisely the same grounds, that it burned before we were born, and that it burns this very day in Cochin-China. It is not from the past to the future, as past and future, that we infer, but from the known to the unknown; from facts observed to facts unobserved; from what we have perceived, or been directly conscious of, to what has not come within our experience. In this last predicament is the wholeregion of the future; but also the vastly greater portion of the present and of the past.
Whatever be the most proper mode of expressing it, the proposition that the course of nature is uniform, is the fundamental principle, or general axiom, of Induction. It would yet be a great error to offer this large generalization as any explanation of the inductive process. On the contrary, I hold it to be...