William Stanley Jevons

And then the difference seems to arise from the deficient harvest, from the growth of population, from the extortion of tradesmen, from anything rather than the change of a British sovereign fresh from the Mint. Value is the most invisible …

Neither in deductive nor inductive reasoning can we add a tittle to our implicit knowledge, which is like that contained in an unread book or a sealed letter. ...Reasoning explicates or brings to conscious possession what was before …

I shall endeavor to show that induction is really the inverse process of deduction.

I protest against deference to any man, whether John Stuart Mill, or Adam Smith, or Aristotle, being allowed to check inquiry. Our science has become far too much a stagnant one, in which opinions rather than experience and reason are …

no school nor clique must be allowed to set up a standard of orthodoxy which shall bar the freedom of scientific inquiry.

Truth indeed is sacred; but, as Pilate said, "What is 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 …

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 …

"we often observe that there is abundance of capital to be had at low rates of interest, while there are also large numbers of artisans starving for want of employment."

I feel quite unable to adopt the opinion that the moment goods pass into the possession of the consumer they cease altogether to have the attributes of capital.

I consider that interest is determined by the increment of produce which it enables a labourer to obtain, and is altogether independent of the total return which he receives for this labour.

Some of the gold possessed by the Romans is doubtless mixed with what we now possess; and some small part of it will be handed down as long as the human race exists.

The whole result of continued labour is not often consumed and enjoyed in a moment; the result generally lasts for a certain length of time. We must then conceive the capital as being progressively uninvested.

One pound invested for five years gives the same result as five pounds invested for one year, the product being five pound years.

What capital I give for the spade merely replaces what the manufacturer had already invested in the expectation that the spade would be needed.

Capital simply allows us to expend labour in advance.

An isolated man like Alexander Selkirk might feel the benefit of a stock of provisions, tools and other means of facilitating industry, although cut off from traffic, with other men.

Ina regular and constant employment the greatest result will always be gained by such a rate as allows a workman each day,or each week at the most, to recover all fatigue and recommence with an undiminished store of energy.

A spade may be made of any size, and if the same number of strokes be made in the hour, the requisite exertion will vary nearly as the cube of the length of the blade.

Over-production is not possible in all branches of industry at once, but it is possible in some as compared to others.

We shall never have a science of economics unless we learn to discern the operation of law even among the most perplexing complications and apparent interruptions.

Economists can never be free of from difficulties unless they will distinguish between a theory and the application of a theory.

"that in the same open market, at any one moment, there cannot be two prices for the same kind of article,"

The difficulties of economics are mainly the difficulties of conceiving clearly and fully the conditions of utility.