The young specialist in English Lit, ... lectured me severely on the fact that in every century people have thought they understood the Universe at last, and in every century they were proved to be wrong. It follows that the one thing we can say about our modern 'knowledge' is that it is wrong. ... My answer to him was, "... when people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together."

In between he spent three years during World War II working as a civilian at the Philadelphia Navy Yard's Naval Air Experimental Station. During his oral examination shortly thereafter Asimov grew concerned at the scrutiny he received. He especially worries that Israel has been created among hostile neighbours and that Jews have merely created for themselves another "Jewish ghetto".

His only works in the 100s—which covers philosophy and psychology—were forewords for The Humanist Way (1988) and In Pursuit of Truth (1982) a festschrift in honor of philosopher Sir Karl Popper's 80th birthday. He often provides nationalities birth dates and death dates for the scientists he mentions as well as etymologies and pronunciation guides for technical terms. Asimov wrote the Lucky Starr series of juvenile science-fiction novels using the pen name Paul French.