How did Jean-Paul Sartre's study The Family Idiot interpret Gustave Flaubert's life?

Jean-Paul Sartre’s The Family Idiot (L’Idiot de la famille) is a massive, multi-volume study that sought to provide a "total biography" of the 19th-century novelist Gustave Flaubert.1

Rather than relying on a single analytical framework, Sartre employed a "double tool" to interpret Flaubert’s life:

• Marxist Analysis: He utilized Karl Marx’s concepts of history and social class to situate Flaubert within his specific historical and socioeconomic context.1
• Freudian Psychoanalysis: He applied Sigmund Freud’s insights to explore the "dark recesses" of Flaubert’s mind, focusing specifically on his childhood and family relationships.1

By synthesizing these approaches, Sartre aimed to explain the development of Flaubert’s personality and literary identity through a minutely detailed examination of his life. The work is noted for its immense length and exhaustive analysis, representing a significant shift in Sartre's later career as he attempted to reconcile individual experience with historical and psychological forces.12