Echoing a point made by Steve Horwitz about the Keynes-Hayek relationship, 
but going back even earlier than The Fatal Conceit, Hayek began worrying 
about declining morals in the 1960s, which was of course a period of 
considerable turmoil and questioning of traditional ways of doing things. 
(I remember taking a freshman or sophmore seminar type class on the topic 
of ethical relativism in 1971 - it was by then very much in the air - and 
of an adult neighbor recommending that I read a book about open marriage, 
a book, he said, that could change society just as it had changed his 
life.) 

Hayek's remarks about Keynes in these earlier papers refer to Keynes' 
paper My Early Beliefs, and Keynes is taken by Hayek as an example of a 
person embracing a type of rationalism that leads the person to substitute 
in his own personal evaluations in making moral judgments. 

One can see such references to Keynes in, for example, "Kinds of 
Rationalism" (1964) reprinted in the 1967 Studies volume, pp. 89-90; in 
"The Errors of Rationalism" (1970), reprinted in the 1978 New Studies 
volume, p. 16; and in Law, Legislation and Liberty, vol. 1, pp. 25-26. So 
one doesn't need to wait for The Fatal Conceit for such references. 

The notecards Steve refers to, by the way, were definitely Hayek's, and 
Bartley's task was to reconstruct from them and from various (sometimes 
incomplete and rewritten) chapters a coherent book. 

Bruce Caldwell