We review evidence showing that disagreement in folk and expert philosophical intuitions can be predicted by global, heritable personality traits. The review focuses on recent studies of intuitions about free will, ethics, and intentional action. These findings are philosophically important because they suggest that while some projects cannot be done, other projects must take individual differences in philosophical character into account. But care needs to be taken when interpreting the implications of these individual differences. We illustrate one way that these differences have been abused. We then illustrate two ways that these findings can be legitimately used to help illuminate philosophical issues. Given the large and readily available body of evidence, neglect of persistent and predictable philosophical differences is irresponsible.