The overall aim of this two-part article is to provide a supplement to ability theories of practice in terms of a defense of the following thesis: In situations of social interaction, individuals’ ability to act appropriately sometimes depends on their exercise of the ability directly to perceive normative states. In this Part I, I introduce ability theories of practice and motivate my thesis. Furthermore, I offer an analysis of normative states as response-dependent properties. Last, I work out and defend an account of direct perception that is compatible with individuals being able directly to perceive various everyday phenomena. Drawing on this account, I show in part II, that normative states are sometimes directly perceptible too.