I came to Ford through his collaborator Joseph Conrad, a teenage interest with Coppola's Apocalypse Now led me to Conrad and a love of sailing inspired me to read all his novels while an undergraduate. I read the first two books of Parade's End after graduating.
I always thought Ford made Tietjens an actuary to highlight his fidelity, his trustworthiness. Statistics provides the foundation for our belief, our faith, in science, that is why Bertrand Russell (following Poincare) observed
It is important to realise the fundamental position of probability in science. ... As to what is meant by probability, opinions differ (p 301, An Outline of Philosophy)around the same time Ford was writing Parade's End. So, in making Tietjens an actuary, and the Second Wrangler of his year, Ford is emphasising Tietjen's faithfulness, which is most obvious in his relations with his adulterous wife, Sylvia, and the more compatible Valentine Wannop. Tietjen's character is magnified by placing him alongside the less virtuous, but more successful, MacMaster.
The trajectory of Tietjen's career, the trauma of serving at the front impacted his work as a mathematician, echoes the real life experience of Émile Borel. Borel was the star of his generation of French mathematicians. His 1894 thesis laid the foundations for modern probability theory and within 16 years he had been appointed Deputy-Director of the most prestigious of the French 'grandes écoles' the École normale supérieure. Borel served in the war, but more significanltly, his adopted son was killed at the front. After the war, Borel pre-empted von Neumann's work in Game Theory and established the Institut de Statistiques de l'Université de Paris, but after 1924 abandoned mathematics for politics, serving as a minister and then, in his seventies was active in the Resistance. In his lifetime ha had been awarded the Croix de Guerre, Médaille de la Résistance with rosette, and the Grand Croix Légion d'Honneur.
When thinking about this, I remembered that Tietjens, as a statistician, had a series of battles with government regarding the manipulation of figures. This suggests that not much has changed, with the government still being accused of doctoring the numbers, and modern statisticians still worry about public faith in their figures.
However, in one respect the situation for mathematics now is worse than it was when Parade's End was written. Would a contemporary author of Ford's prestige choose to make a character a mathematician to emphasise their virtue. It suggests that the reputation of mathematics has been in decline since the 1920s when Russell and Ford were writing. Could this be related to G. H. Hardy's 1940 statement
I have never done anything ‘useful’. No discovery of mine has made, or is likely to make, directly or indirectly, for good or ill, the least difference to the amenity of the world. (p 49, A Mathematician's Apology)Hardy's autobiography is significantly different from Borel's. Since this time, British (pure) mathematics, which encompasses probability, has abandoned the world that Tietjens and Borel lived in, and isolated itself in academic cloisters, to everyone's detriment.
As a footnote, Hardy, who is credited with introducing continental 'rigour' (rigour mortis?) , into British mathematics, opposed the Cambridge Mathematical Tripos, on which the Wranglers were selected, because he felt it had ossified British mathematics. That might have been the case, but the Tripos produced more than just pure mathematicians, it delivered leaders in professions as diverse as the law, medicine, the church, politics, as well as actuaries.