Professor Sellars has invited comment on his recent article in Dialogue dealing with the problem of perception. In brief, I believe that he has formulated the question in the right way, but has reached too facile an answer to it. To begin with the area of agreement, Sellars is surely correct in rejecting the empiricism of Locke, Hume, Dewey, Russell and the rest because they either end up with sensations or ideas from which we cannot get back to the real world or else have to reduce the latter to a bewildering proliferation of sensibilia. Second, no theory of perception can be regarded as satisfactory which leaves out of account the physiological data. In this Sellars echoes the complaint of the distinguished neurologist, Russell Brain, that realist philosophers have notably neglected the part played by the body in our perception of the external world. Third, perception results from the dynamic interplay of subject and object in which sensation performs a key role. Sellars recognizes the weakness in most empiricist theories that the activity of the subject is virtually read out of the situation in order to preserve something like the common sense account of the external world.