John Dewey famously argued that Darwin had introduced a new conceptual vocabulary that would completely overhaul the traditional philosophical enterprise. His sense was that the kinds of monumental metaphysical questions that philosophy typically asked about causes, trends and purposes start to look meaningless and willfully unanswerable once we absorb the tough lessons of natural selection. More specifically, Dewey thought that The Origin of Species provided a strong but beneficial dose of philosophical therapy because it illustrated how to simultaneously abandon the lifeless questions of the past while formulating new questions to take their place. Darwin's achievement revealed for Dewey that sometimes philosophical progress is not “an affair of different ways of dealing with old problems, but of relegation of the problems to the attic in which are kept the relics of former intellectual bad taste.” From this perspective, the litmus test for measuring intellectual growth is surprisingly simple. If we examine the concerns that once excited our ancestors and feel only the shudder of regret that so much energy was wasted on a lost cause, we can be reasonably confident that we have taken a few steps forward.