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

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.

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.

My principal work now lies in tracing out the exact nature and conditions of utility. It seems strange indeed that economists have not bestowed more minute attention on a subject which doubtless furnishes the true key to the problems of economics.