Peter Geach obituary | Philosophy

Publish date: 2022-10-16
PhilosophyObituary

Peter Geach obituary

Prominent Catholic philosopher admired for his mastery of logic and work on ethics

There have been several notable Catholic philosophers in the last half century, among them Michael Dummett, but probably none whose Catholicism was so integral to their philosophy as it was for Peter Geach, who has died aged 97. The professor of logic at Leeds University (1966-81), and subsequently professor emeritus, he was admired by philosophers for his mastery of that discipline, and his contributions to the philosophy of language and ethics, while also acclaimed by Cardinal Cahal Daly, the archbishop of Armagh, for his fidelity to divine revelation, and awarded the papal medal Pro Ecclesia et Pontifice (1999).

For Geach, faith neither conflicted with reason nor trumped it: rather, the two nicely dovetailed. He was never a unitary, system-building philosopher, but produced sharp gems of analytical argument that brilliantly lacerated orthodoxies current in philosophy, while often simultaneously bolstering those of Catholicism. Defending the reality of time against JME McTaggart's theories in Truth, Love and Immortality (1979) was an excellent opportunity for reasserting the truth of God's interventions in time and reconciling difficulties in divine foreknowledge; repudiating Locke's memory criterion for personal identity gave scope to rehabilitate the archaic doctrine of bodily resurrection.

Geach's marriage to fellow Catholic philosopher Elizabeth Anscombe was a fertile philosophical coupling like that of Jean-Paul Sartre and Simone de Beauvoir, only in the Geaches' case, literally so, since they had four daughters and three sons. They were a daunting duo in philosophical debate, and collaborated in translating Descartes, and in the movement (later called Analytical Thomism) to connect analytic philosophy with the thought of Thomas Aquinas. If anything, though, she was the more renowned philosopher of the two.

Geach was born in Chelsea, London. His father, who worked in the Indian Educational Service, was a professor of philosophy in Lahore, and later head of a teacher training college at Peshawar, but Geach spent much of his childhood in Cardiff with his maternal grandparents, who were Polish immigrants.

At the age of eight he became a boarder at Llandaff Cathedral school. He studied classics and philosophy at Balliol College, Oxford, and converted to Catholicism while a student.

In 1938, the year he graduated, he met Anscombe at a Corpus Christi procession and they married in 1941, after he had ensured that she was reliably Catholic. He refused to fight in the second world war, since, although he thought there was a satisfactory jus ad bellum – in line with the Catholic doctrine of the just war – he suspected there would not be jus in bello – right conduct within war.

After doing philosophical research at Cambridge, he became assistant lecturer in philosophy at Birmingham University in 1951, later senior lecturer, then reader in logic there. His and Max Black's translation of works by the German mathematician and logician Gottlob Frege appeared in 1952.

Geach's own first book, Mental Acts (1957), now a classic in the philosophy of psychology, argued that "acquiring a concept is a process of becoming able to do something" – not, as many philosophers since Descartes had held, a matter of having internal representations of external things, or undergoing inner experiences. Geach criticised what he called abstractionism, the view that we acquire the concept of red, say, from repeated experiences of red. It would, he said, fail to account for many of our concepts. "Nowhere in the sensible world could you find anything, nor could you draw any picture, that could suitably be labelled 'or' or 'not'."

Mental Acts was much indebted to Wittgenstein. More original and in line with his distinctive technique of using hard logic to crack problems in metaphysics and ethics was his paper Ascriptivism (1960). Here he showed by means of "if" sentences the inadequacy of ethical theories which claim that to call a person, act or principle good or bad is just a matter of commending or expressing disapproval of the person, act or principle, without any possibility of referring to a real quality they have, or of being accurate about that quality. He made what he called "the Frege point", and later came to be called the Frege-Geach point, commenting that the word "wrong" in the sentence "If Bill did wrong, he will be punished," has the same meaning whether or not the person saying this believes that Bill did wrong.

"Good" and "bad" are anyway, Geach had argued in an article of 1956, nearly always attributive: adjectives integrally related to the terms they qualify. "X is good" is an incomplete assertion – the relevant criteria for saying Bill, or this horse, or this pen, is good depend on what sort of thing each is. It only makes sense to, say "X is a good F" (at least implicitly), and then the truth or falsity of saying so can be ascertained by finding out the function and nature of F. A pen, a horse, a man are good if they fulfil certain criteria. Bill might be a good engineer and a good thief, but a bad man. A man, however, unlike a horse, is not purely biological. We (properly) call him good not on behalf of our own preferences or purposes but of his own.

Geach was a great influence on Philippa Foot, who borrowed Geach's thought experiment of whether a fat man stuck at the mouth of a pothole should be killed in order to save the people inside. Inevitably, Geach himself thought not, and used this example when arguing that, where a mother's life is at stake unless her unborn child is killed, no intervention should occur, since their lives are of equal importance.

He and Anscombe were very traditional on matters of sexual morality, and in 1968 they toasted the Humanae Vitae encyclical, which forbade Catholics' use of contraception, with champagne. They were fairly liberal with their children, however, and dismissive of cleanliness or supervision. On opening the door to a policeman and a lost child, Geach shouted into the house: "Elizabeth, is it one of ours?" It was.

From 1971 to 1974 Geach gave the Stanton Lectures at Cambridge on the philosophy of religion. His theory of relative identity, elaborated in Logic Matters (1972), argued that it makes no sense to say that one thing is the same as something else unless you say what sort of category the two things which are putatively one thing belong to. They may be the same in some respects but not others – a clue, Geach thought, to the baffling doctrine of the Holy Trinity, according to which God the Father, God the Son and God the Holy Ghost are all different persons yet the same god.

Geach was a wonderful lecturer and great stylist. He wrote in a direct, pointed, elegant, almost Johnsonian way, and had a capacity to produce crisp epigrammatic terms that entered the philosophical lexicon, such as "pronouns of laziness" for pronouns that only commonsensically, not grammatically, refer to something.

He tended to look over people's shoulders when talking to them, as if at some impersonal truth, was famously irascible and failed to suffer gladly anything he considered to conflict with Catholic doctrine, even if uttered by respected clerics. He once stood up during a sermon, shouting "This is heresy", and marched his family out of the church. In Who's Who he listed his recreations as "Reading stories of detection, mystery and horror; collecting and annotating old bad logic texts".

Elizabeth died in 2001. He is survived by his children.

Peter Thomas Geach, philosopher, born 29 March 1916; died 21 December 2013

This article was amended on 27 December 2013. The original gave the date of the Humanae Vitae encyclical as 1962. It was further amended on 31 December 2013, when philosophy was added to classics as the subject of Geach's degree.

ncG1vNJzZmivp6x7tbTEoKyaqpSerq96wqikaJ2UqrCiwMiopWhqYGaAcLDEnGZrbl%2BlsrWx0WaenpmTnQ%3D%3D