Four answers to the title question are critically reviewed. (a) The first answer proposes that we perceive our brain events, certain occurrences in our brain that appear to us as parts of the environment. (b) Gestalt psychology distinguishes the phenomenal from the physical and proposes that we always perceive some aspect of our own phenomenal world--which is isomorphic but not identical to certain of our brain events. (c) J. J. Gibson held that our perceptual experiences are registrations of properties of the external environment--which is, therefore, perceived directly (i.e., without experiencing anything else). (d) The fourth answer comprehends perceptual experience to be a qualitative form of noninferential awareness of the apparent properties of specific environmental things. It differs from Gibson's answer in several respects, including the claim that some aspect of the external world appears to us whenever we have perceptual experience.