Non-cognitive dispositions have recently become psychological constructs of interest in the education, economics, philosophy, sociology, and psychology literature. In this article, I draw the distinction between property-first and measurement-first approaches to understanding the meaning of a particular non-cognitive disposition theoretical term, "grit", as well as the relationship between this term and its corresponding measurement procedure. I argue that, depending on which approach one takes, one is confronted with different norms for judging the success of any disposition-measurement procedure pair, meaning that the difference in philosophical approaches may have practical import. I argue that the measurement-first approach is the one educators and educational policy-makers ought to adopt towards grit as it is less likely to lead to over-valuing grit in situations where a gritty disposition may be harmful, better respects scientific virtues and values, and provides a clearer understanding of grit than the property-first approach.