Dr Hemming was one of the drivers behind the introduction of personal, social and health education.
Andrew Copson, of the British Humanist Association, said: "Moral education used to be all to do with RE. He worked to separate morality from religion. He opposed the idea that without religion, people would be immoral."
PSHE has been a non-statutory part of the national curriculum since 2000. It includes drugs and sex education, but also topics such as challenging racism, respecting different cultures and how to negotiate and compromise in relationships.
Mr Hemmings wrote several books on moral education and appeared as a witness for the defence in the trial of Penguin Books for publishing Lady Chatterley's Lover in 1960.