Truth above all things: G. G. Stokes

George Gabriel Stokes is one of three great mathematicians associated with Ireland in the 19th century. If Boole translated classical logic into algebra, while Rowan Hamilton used metaphysics as an inspiration for mathematics, Stokes took a third path. His mathematics was inspired by real life problems. As Lord Kelvin wrote in Stokes’ obituary, (memoirs, p. 317)

In pure mathematics he was recognised as a fruitful worker by the whole scientific world. But with Stokes, mathematics was the servant and assistant, not the master. His guiding star was natural philosophy. Sound, light, radiant heat, chemistry, were his fields of labour

George Gabriel Stokes was born in the rectory at Skreen, Co. Sligo on 13th August, 1819, descended from a family with mathematical and medical leanings. He was first taught mathematics by the parish clerk who recorded him as “working out for himself new ways of doing sums, better than the book” (Wood, 1995, p. 52). He was later sent to school in Dublin, then Bristol. Stokes entered Pembroke College, the third oldest in Cambridge, as an undergraduate in 1837. He stayed there for the rest of his life, serving as Lucasian Professor of Mathematics from 1849 until his death. However he returned to Ireland regularly for the summer vacation. In his paper “On the theory of oscillatory waves” he breaks from mathematical equations to speak of “the surf which breaks upon the western coasts as the result of storms out in the Atlantic” (Wood, 1995, p. 51). Alaistar Wood’s “George Gabriel Stokes 1819 – 1903: An Irish Mathematical Physicist” gives the most detailed picture of Stokes in the Irish context (TCD pdf, html transcription).

Kelvin tells us that Stokes ranged over the whole sphere of natural philosophy. He established the science of hydrodynamics with his law of viscosity (Stokes’ Law) describing the velocity of a small sphere through a viscous fluid . He made important contributions to optics and mathematical physics (including the first version of what is now known as Stokes’ theorem). He was secretary, then president, of the Royal Society. His page on Wikipedia gives a long list of legacies and honours he received. Kelvin and others would say this list is incomplete – he was ready to assist others in Cambridge with their work and didn’t publish all his innovative ideas (for example the application of light to prismatic analysis of light to solar and stellar chemistry.)

Stokes is described as cautious in his work. While innovative in investigation, he restrained himself from speculation. In a letter of 1872, he particurarlly recommends against introducing speculative theories too early to students, because it leads to a student “to accept as dogma what he ought to accept, if he accepts it at all, on account of the simplicity it explains and groups together the known facts” (Larmour, 1907, Vol 1, p. 218).

This reflects his philosophy of (natural) science, which is almost the exact opposite of that held by William Rowan Hamilton (Larmour, 1922, Vol 3, p. 233-4):

[T]he object of the philosopher is not to complicate, but simplify and analyze, so as to reduce phenomena to laws, which in their turn may be made the stepping stones for ascending to a general theory which shall embrace them all…”

Stokes saw science as understanding observable regularities by finding the lawful relationships that govern them. These relationships might lead to the discovery of more fundamental theory, yet the original laws retained their truth independent of that fundamental theory. Stokes often sought laws that could be formulated independently of the ontological commitments of overarching theory – commitments such as how in detail fluids were composed or the nature of the luminiferous aether.

As well as Boole and Hamilton, there are obvious parallels to the other two great Victorian scientists associated with Ireland: John Tyndall and William Thomson, Lord Kelvin (apparently the only one of the five who didn’t branch into philosophy.)

Stokes, like Tyndall, was involved in the post-Darwinian debate. He gave the
Gifford Lectures twice, in 1891 and 1893, both times discussing science and religious belief, and the apparent conflict between the two. The lectures reflect the theological debate of the time: Stokes for instance argues against the theological view that if God affects his creation from time to time that means creation was not perfect, which is derogatory to God. “Do we exault our ideas of the Almighty,” Stokes asks, “by assimilating him to the God of the Epicureans, who created the world and left it all to itself?” (Stokes, 1893, p. 154).

Stokes makes clear his religious convictions and belief in revelation. In his estimation, there is no difficulty in reconciling cosmological and geological evolution with theism. He agrees that that universe changes over time. Neither does he have a particular problem with Darwinian evolution. His main issue is around the origin of life. He argues (in line with his philosophy of science) that assuming spontaneous generation of life must have occurred, and excluding the possibility of divine creation suggests a certain animus towards the idea of creation. The evidence for spontaneous generation is hardly overwhelming: there is no evidence of it happening, nor any experiment showing it is possible in principle. He asks if any natural process exists “that seems so far akin to the origination of living from dead matter as to raise some degree of probability that such a thing is possible by natural causes?” (Stokes, 1891, p .170). Unlike the cases of cosmological and geological change, Stokes thinks, there is not. Given how different spontaneous generation would be from anything we see in nature, “it would require the strongest experimental evidence to lead us to accept the possibility” (Stokes, 1893, p. 148).

George Gabriel Stokes died in Cambridge on 1st February, 1903 and is buried there in the Mill Road Cemetery. There is a memorial to him in St Andrew’s Church Malahide, put up by his sister Elizabeth Stokes, who lived there. It describes him as “seeking truth above all things”. In 1995 a monument dedicated to him was established in Skreen, Co. Mayo (images of Skreen and the monument here and here).

Featured Image: Sir George Gabriel Stokes, 1st Bt by George William De Saulles
bronze medallion, 1899 NPG 2758
© National Portrait Gallery, London

References and Further Reading

Robert W. Batterman and Thomas Duddy (2004) “Stokes, George Gabriel (1819-1903)” in Thomas Duddy (ed) Dictionary of Irish Philosophers, pp. 312-314.

Thomas Duddy (2002) A History of Irish Thought, pp. 262-264.

Alaistar Wood (1995) “George Gabriel Stokes 1819 – 1903: An Irish Mathematical Physicist” in IMS Bulletin, 35, pp. 49-58 (TCD pdf, also transcribed here with a photo of the monument in Skreen)

A. Kinsella (1995) “Sir George Gabriel Stokes: The Malahide Connection” in pp. 59-62 (TCD pdf)

The Gifford Lectures: George Gabriel Stokes.

MacTutor History of Mathematics: George Gabriel Stokes.

G. G. Stokes (1891) Natural Theology: The Gifford Lectures delivered before the University of Edinburgh in 1891 (Archive.org)

G. G. Stokes (1893) Natural Theology: The Gifford Lectures delivered before the University of Edinburgh in 1893 (archive.org)

Joseph Larmour (ed) (1907) Memoir and scientific correspondence of the late Sir George Gabriel Stokes, bart.

• Volume 1 (archive.org)
• Volume 2 (archive.org)

Joseph Larmour (ed) (1922) Mathematical and physical papers 5 volumes

• volume 3 (archive.org)