People have some crazy opinions. Generally, these are the opinions that we disagree with. The standard view in both academia and the wider culture is that people have such opinions due to knowledge deficits; they are lacking information. On this view, providing information and critical reasoning skills is the best way to get opinions to converge, because they’ll converge to the truth. There is already a strong reason to doubt this deficit model. I provide more in the form of evidence that knowledge is unrelated to attitudes about issues. In contrast, a person’s ideology influences both their attitudes and their sense of understanding. A competitor to the deficit model, the cultural cognition view, explains the effect of ideology on attitudes but does not address the sense of understanding. I follow the cultural cognition view in proposing that people outsource much of their reasoning to their communities; I add that it is the resulting sense of understanding that mediates their attitudes. This community of knowledge suggests that people outsource most of their reasoning. I show how this fact can be deployed to bring evidence to bear on policy.