 Foucault argues that from Descartes up to Kant (during what he calls the Classical Age) representation was simply assimilated to thought: to think was to employ ideas to represent the object of thought. But, he says, we need to be clear about what it meant for an idea to represent an object. This was not, first of all, any sort of relation of resemblance: there were no features (properties) of the idea that themselves constituted the representation of the object. (Saying this, however, does not require that the idea itself have no properties or even that these properties are not relevant to the idea’s representation of the object.) By contrast, during the Renaissance, knowledge was understood as a matter of resemblance between things.