Complex sentence: He credited Marcuse with providing a "wide-ranging revaluation of narcissism" that shows it to be a "potentially emancipatory force", and compared Marcuse's views on narcissism to those of the psychoanalysts Béla Grunberger and Janine Chassesguet-Smirgel.
Split into simpler sentences: He credited Marcuse with providing a "wide-ranging revaluation of narcissism" that shows it to be a "potentially emancipatory force". He compared Marcuse's views on narcissism to those of the psychoanalysts Béla Grunberger and Janine Chassesguet-Smirgel.