An idealized view of science is that theories are accepted or rejected based solely on empirical evidence. In fact, science is not simply an objective search for truth, but also a social process, in which proponents of a theory must convince other scientists, through logic and argumentation, of how evidence should be interpreted.
However, this process advantages incumbent theories over challengers for a number of reasons, including confirmation bias, social proof, ideological complacency, and the vested interests of scientists whose reputations and even sense of self are tied to existing theories. A consequence is scientific inertia, where weak or ill-founded theories take on a life of their own, sometimes even gaining momentum despite evidence that puts their veracity in doubt.