These successors, on Barry’s telling, include such rational choice theorists as Mancur Olson and Anthony Downs, amongst others. Alan Ryan concurs. Although “an eminently dislikable document,” Ryan writes, Mill’s Essay on Government “has virtues that ought not to be neglected.” One of these is that it “stands at the head of a line of thought extending down to Joseph Schumpeter and Anthony Downs, a line of thought that provides many of the explicit or implicit assumptions with the aid of which we still practice political science” (Ryan 1972, 82–83).