In this critical review, I focus on two things. First, I respond to Stang’s interpretation of Descartes, according to which Descartes’ endorsement of his ontological argument commits him to possibilism, the doctrine that there are, or at least could be, non-existent individuals. My response consists in presenting a version of Descartes’ argument the acceptance of which does not require the acceptance of possibilism. The second thing I focus on is Stang’s claim that Kant distinguishes several kinds of real possibility. I raise worries about Stang’s formulations of various doctrines of real possibility, and I preliminarily explore how real essence and ground are connected with the various kinds of real necessity Stang’s Kant recognizes.