Richard Levins, the great radical and scientist, passed away on January 19. Levins was a profound thinker who made foundational contributions to scientific and intellectual fields ranging from community ecology and evolutionary theory to mathematical biology, public health, and the philosophy of science.

His extraordinary scientific legacy is matched by his legacy as a radical and activist. Blacklisted in 1950s for his activism, Levins subsequently moved to Puerto Rico with Rosario Morales, his wife and lifelong partner, and became an important member of the Puerto Rican independence and antiwar movements.

Levins was also a leading intellectual figure in the fight against biological determinism and remained an activist to the end of his life, often lecturing on his favorite topic: the use of dialectics to understand complexity and change in both the natural and social sciences.