To address questions of scientific responsibility does not necessarily imply that one needs technical competence in a particular field (e.g. biology) to evaluate certain technical matters.

Most are at the graduate level. Books
He was a prolific writer of mathematical texts often completing one on his summer vacation.  285–325).

He held faculty positions at the University of Chicago and Columbia University (from 1955 leaving in 1971 in a dispute). At the time of his death he was professor emeritus of mathematics at Yale University.