Peter Kropotkin was surely on the left. He was one of the founders of what is now called 'sociobiology' or 'evolutionary psychology' with his book Mutual Aid, arguing that human nature had evolved in ways conducive to the communitarian anarchism that he espoused.
Noam ChomskyThe freer the society gets, the more dangerous the great beast becomes and the more you have to be careful to cage it somehow.
Noam ChomskySouth America has virtually broken away in the last decade. That's an event of historic significance. South America just doesn't follow US orders. In fact there isn't a single US military base left there.
Noam ChomskyI felt that we could hardly improve on the conception of the university expressed by one of the founders of the modern system, Wilhelm von Humboldt, also one of the founders of classical liberalism. That seems to me true today as well, though ideals of course have to be adapted to changing circumstances.
Noam Chomsky