Frasi di William Stanley Jevons

Preface To The Second Edition, p. 7.
The Theory of Political Economy (1871)
Contesto: In short, I do not write for mathematicians, nor as a mathematician, but as an economist wishing to convince other economists that their science can only be satisfactorily treated on an explicitly mathematical basis.

Letter to Henrietta Jevons (28 February 1858), published in Letters and Journal of W. Stanley Jevons (1886), edited by Harriet A. Jevons, his wife, p. 101.
Contesto: You will perceive that economy, scientifically speaking, is a very contracted science; it is in fact a sort of vague mathematics which calculates the causes and effects of man's industry, and shows how it may be best applied. There are a multitude of allied branches of knowledge connected with mans condition; the relation of these to political economy is analogous to the connexion of mechanics, astronomy, optics, sound, heat, and every other branch more or less of physical science, with pure mathematics.

The Substitution of Similars, The True Principles of Reasoning (1869)
Contesto: Aristotle's dictim... may then be formulated somewhat as follows:—Whatever is known of a term may be stated of its equal or equivalent. Or, in other words, Whatever is true of a thing is true of its like.... the value of the formula must be judged by its results;... it not only brings into harmony all the branches of logical doctrine, but... unites them in close analogy to the corresponding parts of mathematical method. All acts of mathematical reasoning may... be considered but as applications of a corresponding axiom of quantity...

The Substitution of Similars, The True Principles of Reasoning (1869)
Contesto: Aristotle's dictim... may then be formulated somewhat as follows:—Whatever is known of a term may be stated of its equal or equivalent. Or, in other words, Whatever is true of a thing is true of its like.... the value of the formula must be judged by its results;... it not only brings into harmony all the branches of logical doctrine, but... unites them in close analogy to the corresponding parts of mathematical method. All acts of mathematical reasoning may... be considered but as applications of a corresponding axiom of quantity...

Preface To The Second Edition, p. 6.
The Theory of Political Economy (1871)
Contesto: A correspondent, Captain Charles Christie R. E., to whom I have shown these sections after they were printed, objects reasonably enough that commodity should not have been represented by M, or Mass, but by some symbol, for instance Q, which would include quantity of space or time or force, in fact almost any kind of quantity.

Origine: The Theory of Political Economy (1871), Chapter I, Introduction, p. 44.
Contesto: A correct theory is the first step towards improvement, by showing what we need and what we might accomplish.

Origine: The Principles of Science: A Treatise on Logic and Scientific Method (1874) Vol. 1, p. 14

Origine: The Theory of Political Economy (1871), Chapter I, Introduction, p. 53.

Origine: The Theory of Political Economy (1871), Chapter IV, Theory of Exchange, p. 108.

Preface To The Second Edition, p. 31.
The Theory of Political Economy (1871)
Contesto: There is no such thing as absolute cost of labour; it is all a matter of comparison. Every one gets the most which he can for his exertions; some can get little or nothing, because they have not sufficient strength, knowledge or ingenuity; others get much, because they have, comparatively speaking, a monopoly of certain powers.

Who could have conceived that the investigation of petty games of chance would have led to the most sublime branch of mathematical science - the theory of probabilities?
Origine: The Theory of Political Economy (1871), Chapter I, Introduction, p. 41.

The Coal Question (1865)
Contesto: It is very commonly urged, that the failing supply of coal will be met by new modes of using it efficiently and economically.... It is wholly a confusion of ideas to suppose that the economical use of fuel is equivalent to a diminished consumption. The very contrary is the truth.

Preface To The Second Edition, p. 27-28.
The Theory of Political Economy (1871)
Contesto: The conclusion to which I am ever more clearly coming is that the only hope of attaining a true system of economics is to fling aside, once and forever, the mazy and preposterous assumptions of the Ricardian school. Our English economists have been living in a fool's paradise. The truth is with the French school, and the sooner we recognize the fact, the better it will be for all the world, except perhaps the few writers who are far too committed to the old erroneous doctrines to allow for renunciation.

Reflections on his earlier life, written when he was 27 (December 1862), published in Letters and Journal of W. Stanley Jevons (1886), edited by Harriet A. Jevons, his wife, p. 13.
Contesto: It was during the year 1851, while living almost unhappily among thoughtless, if not bad companions, in Gower Street a gloomy house on which I now look with dread it was then, and when I had got a quiet hour in my small bedroom at the top of the house, that I began to think that I could and ought to do more than others. A vague desire and determination grew upon me. I was then in the habit of saying my prayers like any good church person, and it was when so engaged that I thought most eagerly of the future, and hoped for the unknown. My reserve was so perfect that I suppose no one had the slightest comprehension of my motives or ends. My father probably knew me but little. I never had any confidential conversation with him. At school and college the success in the classes was the only indication of my powers. All else that I intended or did was within or carefully hidden. The reserved character, as I have often thought, is not pleasant nor lovely. But is it not necessary to one such as I? Would it have been sensible or even possible for a boy of fifteen or sixteen to say what he was going to do before he was fifty? For my own part I felt it to be almost presumptuous to pronounce to myself the hopes I held and the schemes I formed. Time alone could reveal whether they were empty or real; only when proved real could they be known to others.

Origine: The Theory of Political Economy (1871), Chapter VIII : Concluding Remarks, The Noxious Influence of Authority, p. 220.
Contesto: Truth indeed is sacred; but, as Pilate said, "What is truth?" Show us the undoubted infallible criterion of absolute truth, and we will hold it as a sacred inviolable thing. But in the absence of that infallible criterion, we have all an equal right to grope about in our search of it, and no body and no school nor clique must be allowed to set up a standard of orthodoxy which shall bar the freedom of scientific inquiry.

Origine: The Theory of Political Economy (1871), Chapter VIII : Concluding Remarks, The Noxious Influence of Authority, p. 220.
Contesto: To me it is far more pleasant to agree than to differ; but it is impossible that one who has any regard for truth can long avoid protesting against doctrines which seem to him to be erroneous. There is ever a tendency of the most hurtful kind to allow opinions to crystallise into creeds. Especially does this tendency manifest itself when some eminent author, enjoying power of clear and comprehensive exposition, becomes recognised as an authority. His works may perhaps be the best which are extant upon the subject in question; they may combine more truth with less error than we can elsewhere meet. But "to err is human," and the best works should ever be open to criticism. If, instead of welcoming inquiry and criticism, the admirers of a great author accept his writings as authoritative, both in their excellences and in their defects, the most serious injury is done to truth. In matters of philosophy and science authority has ever been the great opponent of truth. A despotic calm is usually the triumph of error. In the republic of the sciences sedition and even anarchy are beneficial in the long run to the greatest happiness of the greatest number.

The Coal Question (1865)
Contesto: The alternatives before us are simple. Our empire and race already comprise one-fifth of the world's population, and by our plantation of new states, by our guardianship of the seas, by our penetrating commerce, by the example of our just laws and firm constitution, and above all by the dissemination of our new arts, we stimulate the progress of mankind in a degree not to be measured. If we lavishly and boldly push forward in the creation and distribution of our riches, it is hard to over-estimate the pitch of beneficial influence to which we may attain in the present. But the maintenance of such a position is physically impossible. We have to make the momentous choice between brief greatness and longer continued mediocrity.

Preface
The Substitution of Similars, The True Principles of Reasoning (1869)
Contesto: The new and wonderful results of the late Dr. Boole's mathematical system of Logic appear to develop themselves as most plain and evident consequences of the self-same process of substitution, when applied to the Primary Laws of Thought. Should my notion be true, a vast mass of technicalities may be swept from our logical text-books, and yet the small remaining part of logical doctrine will prove far more useful than all the learning of the Schoolmen.

Origine: The Theory of Political Economy (1871), Chapter VIII : Concluding Remarks, The Noxious Influence of Authority, p. 220.
Contesto: To me it is far more pleasant to agree than to differ; but it is impossible that one who has any regard for truth can long avoid protesting against doctrines which seem to him to be erroneous. There is ever a tendency of the most hurtful kind to allow opinions to crystallise into creeds. Especially does this tendency manifest itself when some eminent author, enjoying power of clear and comprehensive exposition, becomes recognised as an authority. His works may perhaps be the best which are extant upon the subject in question; they may combine more truth with less error than we can elsewhere meet. But "to err is human," and the best works should ever be open to criticism. If, instead of welcoming inquiry and criticism, the admirers of a great author accept his writings as authoritative, both in their excellences and in their defects, the most serious injury is done to truth. In matters of philosophy and science authority has ever been the great opponent of truth. A despotic calm is usually the triumph of error. In the republic of the sciences sedition and even anarchy are beneficial in the long run to the greatest happiness of the greatest number.

Reflections on his earlier life, written when he was 27 (December 1862), published in Letters and Journal of W. Stanley Jevons (1886), edited by Harriet A. Jevons, his wife, p. 13.
Contesto: It was during the year 1851, while living almost unhappily among thoughtless, if not bad companions, in Gower Street a gloomy house on which I now look with dread it was then, and when I had got a quiet hour in my small bedroom at the top of the house, that I began to think that I could and ought to do more than others. A vague desire and determination grew upon me. I was then in the habit of saying my prayers like any good church person, and it was when so engaged that I thought most eagerly of the future, and hoped for the unknown. My reserve was so perfect that I suppose no one had the slightest comprehension of my motives or ends. My father probably knew me but little. I never had any confidential conversation with him. At school and college the success in the classes was the only indication of my powers. All else that I intended or did was within or carefully hidden. The reserved character, as I have often thought, is not pleasant nor lovely. But is it not necessary to one such as I? Would it have been sensible or even possible for a boy of fifteen or sixteen to say what he was going to do before he was fifty? For my own part I felt it to be almost presumptuous to pronounce to myself the hopes I held and the schemes I formed. Time alone could reveal whether they were empty or real; only when proved real could they be known to others.

Reflections on his earlier life, written when he was 27 (December 1862), published in Letters and Journal of W. Stanley Jevons (1886), edited by Harriet A. Jevons, his wife, p. 11.
Contesto: When quite young I can remember I had no thought or wish of surpassing others. I was rather taken with a liking of little arts and bits of learning. My mother carefully fostered a liking for botany, giving me a small microscope and many books, which I yet have. Strange as it may seem, I now believe that botany and the natural system, by exercising discrimination of kinds, is the best of logical exercises. What I may do in logic is perhaps derived from that early attention to botany.

The Coal Question (1865)
Contesto: Commerce is but a means to an end, the diffusion of civilization and wealth. To allow commerce to proceed until the source of civilization is weakened and overturned is like killing the goose to get the golden egg. Is the immediate creation of material wealth to be our only object?

Reflections on his earlier life, written when he was 27 (December 1862), published in Letters and Journal of W. Stanley Jevons (1886), edited by Harriet A. Jevons, his wife, p. 13.
Contesto: It was during the year 1851, while living almost unhappily among thoughtless, if not bad companions, in Gower Street a gloomy house on which I now look with dread it was then, and when I had got a quiet hour in my small bedroom at the top of the house, that I began to think that I could and ought to do more than others. A vague desire and determination grew upon me. I was then in the habit of saying my prayers like any good church person, and it was when so engaged that I thought most eagerly of the future, and hoped for the unknown. My reserve was so perfect that I suppose no one had the slightest comprehension of my motives or ends. My father probably knew me but little. I never had any confidential conversation with him. At school and college the success in the classes was the only indication of my powers. All else that I intended or did was within or carefully hidden. The reserved character, as I have often thought, is not pleasant nor lovely. But is it not necessary to one such as I? Would it have been sensible or even possible for a boy of fifteen or sixteen to say what he was going to do before he was fifty? For my own part I felt it to be almost presumptuous to pronounce to myself the hopes I held and the schemes I formed. Time alone could reveal whether they were empty or real; only when proved real could they be known to others.

Origine: The Principles of Science: A Treatise on Logic and Scientific Method (1874) Vol. 1, pp. 257, 260 & 271

Origine: The Theory of Political Economy (1871), Chapter VII, Theory of Capital, p. 206.

Introduction, Lesson I: Definition and Sphere of the Science.
Elementary Lessons on Logic (1870)

Origine: The Theory of Political Economy (1871), Chapter III, Theory of Utility, p. 65.

Origine: The Theory of Political Economy (1871), Chapter I, Introduction, p. 51.

William Stanley Jevons, The Theory of Political Economy (1871). Preface To The Second Edition, p. 14.
The Theory of Political Economy (1871)