This is a man who, when a friend he greatly respected purchased for him a ticket to an opera, snuck away during the commotion in the lobby of the amphitheater, ran back to the box office and refunded the ticket. He took the money and ran. Of the incident, he wrote, “There are moments when a man is seized by a sort of madness and should not be judged by his actions.” He loved providing these little justifications.
In A History of Western Philosophy Bertrand Russell possessed dim views of Rousseau’s political philosophy (“Hitler is the outcome of Rousseau”) and a low opinion of Rousseau’s character (he was “destitute of all the ordinary virtues”). Russell used some of the examples of this piece, too, including Rousseau’s abandonment of a friend who was seizing, and of shuffling all of his children to orphanages.
Francis Fukuyama’s The Origins of Political Order noted (and this was new to me, at least) that Rousseau’s “social contract” idea is dubious and, historically, probably wrong. (I profess to never having read Emile, though, nor none of Rousseau’s actual writings, so I am very far from an expert on such things—but even his theology, which rejected all theretofore intellectual arguments for the existence of God simply by the equivalent of throwing up his hands, seems wrong.)
Anyway, regardless of the quality of his ideas, in person, Rousseau was, well, not a nice guy.