William Stanley Jevons
William Stanley Jevons FRS (/ˈdʒɛvənz/;[2] 1 September 1835 – 13 August 1882) was an English economist and logician.
William Stanley Jevons
1 September 1835
13 August 1882 (aged 46)
University College London (1876–1880)
Owens College (now University of Manchester) (1863–1875)
Irving Fisher described Jevons's book A General Mathematical Theory of Political Economy (1862) as the start of the mathematical method in economics.[3] It made the case that economics, as a science concerned with quantities, is necessarily mathematical.[4] In so doing, it expounded upon the "final" (marginal) utility theory of value. Jevons' work, along with similar discoveries made by Carl Menger in Vienna (1871) and by Léon Walras in Switzerland (1874), marked the opening of a new period in the history of economic thought. Jevons's contribution to the marginal revolution in economics in the late 19th century established his reputation as a leading political economist and logician of the time.
Jevons broke off his studies of the natural sciences in London in 1854 to work as an assayer in Sydney, where he acquired an interest in political economy. Returning to the UK in 1859, he published General Mathematical Theory of Political Economy in 1862, outlining the marginal utility theory of value, and A Serious Fall in the Value of Gold in 1863. For Jevons, the utility or value to a consumer of an additional unit of a product is inversely related to the number of units of that product he already owns, at least beyond some critical quantity.
Jevons received public recognition for his work on The Coal Question (1865), in which he called attention to the gradual exhaustion of Britain's coal supplies and also put forth the view that increases in energy production efficiency leads to more, not less, consumption.[5]: 7f, 161f This view is known today as the Jevons paradox, named after him. Due to this particular work, Jevons is regarded today as the first economist of some standing to develop an 'ecological' perspective on the economy.[6]: 295f [7]: 147 [5]: 2
The most important of his works on logic and scientific methods is his Principles of Science (1874),[8] as well as The Theory of Political Economy (1871) and The State in Relation to Labour (1882). Among his inventions was the logic piano, a mechanical computer.
Background[edit]
Jevons was born in Liverpool, Lancashire, England. His father, Thomas Jevons, was an iron merchant who wrote about legal and economic subjects as well. His mother Mary Anne Jevons was the daughter of William Roscoe. At the age of fifteen he was sent to London to attend the University College School. Around this time, he seemed to have formed the belief that he was capable of important achievements as a thinker. Towards the end of 1853, after having spent two years at University College, where his favourite subjects were chemistry and botany, he received an offer as metallurgical assayer for the new mint in Australia. The idea of leaving the UK was distasteful, but pecuniary considerations had, in consequence of the failure of his father's firm in 1847, become of vital importance, and he accepted the post.[9]
Jevons left the UK for Sydney in June 1854 to take up a role as an Assayer at the Mint. Jevons lived with his colleague and his wife first at Church Hill, then in Annangrove at Petersham and at Double Bay before returning to England. In letters to his family he described his life, took photographs and produced a social map of Sydney. Jevons returned to England via America five years later.[10]
He resigned his appointment, and in the autumn of 1859 re-entered the University College London as a student. He was granted B.A. and M.A. degrees from the University of London. He now gave his principal attention to the moral sciences, but his interest in natural science was by no means exhausted: throughout his life he continued to write occasional papers on scientific subjects, and his knowledge of the physical sciences greatly contributed to the success of his chief logical work, The Principles of Science. Not long after taking his M.A. degree, Jevons obtained a post as tutor at Owens College, Manchester.
In 1866, he was elected professor of logic and mental and moral philosophy and Cobden professor of political economy at Owens College.[9]
Geometry[edit]
One of Jevons's contemporaries, Hermann von Helmholtz, who was interested in non-Euclidean geometry,[29] discussed two groups of two-dimensional creatures with one group living in the plane while the other living in the surface of a sphere. He asserted that since these creatures were embedded in two dimensions, they would develop a planar version of Euclidean geometry, but that since the nature of these surfaces were different, they would arrive at very different versions of this geometry. He then extended this argument into three dimensions, noting that this raises fundamental questions of the relationship of spatial perception to mathematical truth.[30][31][32]
Jevons made an almost immediate response to this article. While Helmholtz focused on how humans perceived space, Jevons focused on the question of truth in geometry. Jevons agreed that while Helmholtz's argument was compelling in constructing a situation where the Euclidean axioms of geometry would not apply, he believed that they had no effect on the truth of these axioms. Jevons hence makes the distinction between truth and applicability or perception, suggesting that these concepts were independent in the domain of geometry.
Jevons did not claim that geometry was developed without any consideration for spatial reality. Instead, he suggested that his geometric systems were representations of reality but in a more fundamental way that transcends what one can perceive about reality.[33] Jevons claimed that there was a flaw in Helmholtz's argument relating to the concept of infinitesimally small. This concept involves how these creatures reason about geometry and space at a very small scale, which is not necessarily the same as the reasoning that Helmholtz assumed on a more global scale. Jevons claimed that the Euclidean relations could be reduced locally in the different scenarios that Helmholtz created and hence the creatures should have been able to experience the Euclidean properties, just in a different representation. For example, Jevons claimed that the two-dimensional creatures living on the surface of a sphere should be able to construct the plane and even construct systems of higher dimensions and that although they may not be able to perceive such situations in reality, it would reveal fundamental mathematical truths in their theoretical existence.[34]
In 1872, Helmholtz gave a response to Jevons, who claimed that Helmholtz failed to show why geometric truth should be separate from the reality of spatial perception. Helmholtz criticized Jevons's definition of truth and in particular, experiential truth. Helmholtz asserts that there should be a difference between experiential truth and mathematical truth and that these versions of truth are not necessarily consistent. This conversation between Helmholtz and Jevons was a microcosm of an ongoing debate between truth and perception in the wake of the introduction of non-Euclidean geometry in the late 19th century.[35]
Personal life[edit]
In 1867, Jevons married Harriet Ann Taylor, whose father, John Edward Taylor, had been the founder and proprietor of the Manchester Guardian. Jevons suffered from ill health and sleeplessness, and found the delivery of lectures covering so wide a range of subjects very burdensome. In 1876, he was glad to exchange the Owens professorship for the professorship of political economy in University College, London. Travelling and music were the principal recreations of his life; but his health continued to be bad, and he suffered from depression. He found his professorial duties increasingly irksome, and feeling that the pressure of literary work left him no spare energy, he decided in 1880 to resign the post. On 13 August 1882 he drowned whilst bathing near Hastings.[9]
Jevons was brought up a Christian Unitarian.[36] Excerpts from his journals indicate he remained committed to his Christian beliefs until death. He is buried in the Hampstead Cemetery.[37]
Legacy[edit]
Jevons was a prolific writer, and at the time of his death was a leader in the UK both as a logician and as an economist. Alfred Marshall said of his work in economics that it "will probably be found to have more constructive force than any, save that of Ricardo, that has been done during the last hundred years."[9]
Jevons's theory of induction has continued to be influential: "Jevons's general view of induction has received a powerful and original formulation in the work of a modern-day philosopher, Professor K. R. Popper."[22]
Works available online