FMRI has been exploited now for over thirty years. So it is time to ask whether it has changed the way we think about the brain. For comparison I briefly review three findings from studies of animals that have made fundamental discoveries about the brain. I suggest four findings from brain imaging that have discovered new principles concerning brain function. However, since brain imaging measures correlations, it is necessary to intervene in the system if we are to demonstrate causal influences. I conclude that FMRI is not sufficient on its own and that a variety of methods need to be used if we are to make progress in understanding how the brain works.