Gil's areas of study are John Dewey’s theory of democracy and education; Matthew Lipman’s practice of philosophy as the methodology of education; the philosophical development of ‘community of inquiry’ in educational discourse; and collaborative inquiry-based teaching and learning through philosophy.  He has written several books in these areas . He has taught educational philosophy for many years and advocates for the value of critical thinking for the health of democratic societies.  Gil has consulted widely for schools to help in the development of programs in philosophy and critical thinking.