His October 1993 Scientific American article, "The Death of Proof", claimed that the growing complexity of mathematics, combined with "computer proofs" and other developments, were undermining traditional concepts of mathematical proof.
Horgan's 1996 book The End of Science begins where "The Death of Proof" leaves off: in it, Horgan argues that pure science, defined as "the primordial human quest to understand the universe and our place in it," may be coming to an end.