This paper aims to briefly survey the epistemological debate about the connection between perception and cognition. Contemporary representationalists agree that both perception and cognition can represent how things are in our environment. They customarily separate two types of content. In the standard version, the content of paradigmatic perceptual processes is held to be nonconceptual. On the other hand, our typical conscious processes, such as thinking or remembering, operate with a representational content that might be called conceptual content. According to Peacocke this disctinction may be used to explain how we can gain a priori knowledge about the world. I argue in the final section that this claim poses a considerable problem, because the notion of the a priori seems to be incompatible with the representationalist's overall position. For this reason I present a new - emergentist - version of Peacocke's thesis.