This is the first book that historically, politically, and anthropologically examines the multiple movements and diverse trends of the French Left from the Age of Enlightenment to today. The Left is associated with the idea of progress at the end of the 18th century, with human rights during the Revolution, with parliamentarism during the period of the terroristic monarchy, with universal suffrage of 1848, with the separation of Church and State during the years of the Third Republic, with the humanization of labor during the Popular Front, and with the power play during the presidency of Mitterrand.

Juliard distinguishes four Lefts: the liberal, the Jacobin, the collectivist, and the libertarian. Each period is illuminated by parallel portraits (in the manner of Plutarch) of Voltaire and Rousseau, Robespierre and Danton, Lamartine and Hugo, Clemenceau and Jaurès, up to Sartre and Camus or Méndès France and Mitterrand.

Jacques Juliard was born in 1933 in Brenod, France. From his student years, he is associated with the Catholicism of the Left and the magazine Esprit. He studied German literature and History and became agrégé in History in 1958. As a student, he was involved in student union activities. He served as vice president of UNEF and developed a strong activity in the anti-colonial struggle in Algeria. He continued his activism in the teachers' union SGEN, initially, and later in CFTC and CFDT. In 1962, alongside his union activities, he began his academic career as a researcher at the CNRS. In 1966 he taught at the Institute of Political Science in Paris and at the Sorbonne University. In 1968 he founded, with Jacques Ozouf, the Department of History at Vincennes University and taught at the Center for Journalism Education (CFJ). In 1976 he ceased his active involvement in unionism and in 1978 was elected director of studies (professor) at the École des Hautes Études en Sciences Sociales.

In 1974, he joined the Socialist Party along with Michel Rocard and Jules Martiné and became one of the key theorists of the "Second Left." In 1978 he took on the role of regular columnist for the weekly magazine Le Nouvel Observateur and rose to the position of deputy director. In 2010, he expressed his opposition to what he considered the rightward shift of the magazine and became a regular columnist for the magazine Marianne. His book Le choc Simone Weil is also being prepared for publication by the Polis editions.