Louise Fiona Richardson gives a talk on philosophy and perception It is beyond dispute that the senses interact. In this paper I will consider the way in which such interaction constrains thought about the senses, and in particular, thought about how they are distinguished from one another. I will consider two views of what it is to have a sense. On the first view, senses are systems. On the second, they are capacities. I will argue that on each view, the occurrence of different forms of multimodal perception rules out some views of how the senses are distinguished. The occurrence of perception not restricted to one sense does not, however, make it impossible to distinguish between the senses, either as systems or capacities. Neither does it make that distinction otiose. And whilst there is an explanatory penalty to be paid if one seeks to explain perception only one sense at a time, I will argue that given a plausible, defensible view of how to count perceptual experiences at a time, interaction between the senses does not show that it is illegitimate to talk of perceptual experiences belonging to one modality, at least whilst thinking of senses as capacities. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/