 Some debates about which properties can be represented in perception focus on specific properties. It is important to distinguish between, first, perceiving causation, on the one hand, and, second, representing causal relations in experience, on the other. It is a substantive question whether the former can happen only if the latter does. The first issue concerns whether one can perceive causation, or whether all one can perceive is a sequence of events, minus its causal nature (assuming there is such a thing). For discussion see Ducasse 1965, Armstrong 1997, Fales 1990, Pietroski 2000, Beebee 2003, Butterfill 2011. For discussion in psychology of cognition regarding causation, see Michotte (1963) and essays in Premack, Premack and Sperber (1995.) The second issue concerns whether experiences can represent causal relations, in the same way they represent colors, shapes and whatever else is plausibly represented in experience.