Abstract: This chapter focuses on three questions: what is a representation? What determines what a representation is a representation of? What makes a representation a piece of knowledge? The answer to the first question gives central place to the notion of truth, and the answers to the second and third appeal to causation. The Causal Truth-Maker Principle is introduced, a principle that will play a prominent part in the following discussion.

Keywords: content, knowledge, causation, truth, truth-maker, Casual Truth-Maker Principle,