C. D. Broad

As his fellowship at Trinity College was a non-residential position, he was also able to accept a position as an assistant lecturer that he had applied for at St Andrews University, where he remained until 1920. That year, he was appointed professor at Bristol University, working there until 1923, when he returned to Trinity as a lecturer. From 1926 until 1931, he was a lecturer in 'moral science' at Cambridge University's Faculty of Philosophy.

Later at Cambridge, he was appointed in 1931 as 'Sidgwick Lecturer', a role he would keep until 1933, when he was appointed Knightbridge Professor of Moral Philosophy at the university, a position he held for twenty years (until 1953).[6] In 1927 he gave the British Academy's Master-Mind Lecture, entitled Sir Isaac Newton.[7]

In addition, Broad was President of the Aristotelian Society from 1927 to 1928, and again from 1954 to 1955. He was also President of the Society for Psychical Research in 1935 and 1958.[6]

Broad was openly homosexual at a time when homosexual acts were illegal. In March 1958, Broad along with fellow philosophers A.J. Ayer and Bertrand Russell, writer J.B. Priestley and 27 others sent a letter to The Times which urged the acceptance of the Wolfenden Report's recommendation that homosexual acts should "no longer be a criminal offence."[8]

Broad argued that if research could demonstrate that psychic events occur, this would challenge philosophical theories of "basic limiting principles" in at least five ways:[9]

1. Backward causation (i.e., the future affecting the past) is rejected by many philosophers, but would be shown to occur if, for example, people could predict the future.
2. One common argument against dualism (i.e., the belief that, while bodies are physical entities, minds are a different, non-physical sort of entity) is that physical and non-physical things cannot interact. However, this would be shown to be possible if people can move physical objects by thought (telekinesis).
3. Similarly, philosophers tend to be skeptical about claims that non-physical 'stuff' could interact with anything. This would also be challenged if minds are shown to be able to communicate with each other, as would be the case if mind-reading is possible.
4. Philosophers generally accept that we can only learn about the world through reason and perception. This belief would be challenged if people were able to psychically perceive events in other places.
5. Physicalist philosophers believe that there cannot be persons without bodies. If ghosts were shown to exist, this view would be challenged.

In his essay "Determinism, Indeterminism, and Libertarianism", Broad argued for non-occurrent causation as "literally determined by the agent or self." The agent could be considered as a substance or continuant, and not by a total cause which contains as factors events in and dispositions of the agent. Thus, our efforts would be completely determined, but their causes would not be prior events. New series of events would then originate, which he called "continuants", which are essentially causa sui.

Peter van Inwagen says that Broad formulated an excellent version of what van Inwagen has called the "Consequence Argument" in defence of incompatibilism.[10]