The chapter focuses on attributions of the transparency of thought to early modern figures, most notably Descartes. Many recent philosophers assume that Descartes believed the mind to be “transparent”: since all mental states are conscious, we are therefore aware of them all, and indeed incorrigibly know them all. Descartes, and Berkeley too, do make statements that seem to endorse both aspects of the transparency theses (awareness of all mental states; incorrigibility). However, they also make systematic theoretical statements that directly countenance “unnoticed” thoughts or mental states, that is, thoughts or mental states of which the subject is unaware and has no knowledge. Descartes, having identified the essence of mind with thought ...