German born Jacques Loeb was both a biologist (nominated for the Nobel Prize in Med. in 1901) & political activist. The authors highlight Loeb's organizational actions & political opinions during the years of 1906 to 1924, the year he died. As a social activist & scientist, Loeb influenced the scientific community, the politically sensitive public, & ultimately the population against conservative & reactionary attitudes toward race, ethnicity, poverty, criminality, war & religion.” He took positions on WW 1, social activism, his influence on the economist Thorstein Veblen & finally philosophy & politics. Loeb was hailed early in his career for his work on spontaneous generation of marine embryos & recognized later for his active challenge to social intolerance.