In 2001, Michael Behe wrote: "is an asymmetry between my current definition of irreducible complexity and the task facing natural selection. I hope to repair this defect in future work." Behe specifically explained that the "current definition puts the focus on removing a part from an already functioning system", but the "difficult task facing Darwinian evolution, however, would not be to remove parts from sophisticated pre-existing systems; it would be to bring together components to make a new system in the first place". In the 2005 "Kitzmiller v. Dover Area School District" trial, Behe testified under oath that he "did not judge [the asymmetry serious enough to revised the book yet."