Sentence:  During the late 1950s and throughout the 1960s, this commitment brought him into frequent critical confrontation with entrenched forms of conservative thinking (in academic areas from history and social science to the more <WSD>abstract</WSD> domains of ethical and political philosophy),... 
Meaning of the word marked with <WSD> tags:  Apart from practice or reality; vague; theoretical; impersonal; not applied.