  Another well-known set of Gassendi's objections target Descartes' views of mind and body. One such objection is a prelude to the well-known puzzle over how mind and body could be thought to interact, posed by Princess Elisabeth of Bohemia. Gassendi wonders how Descartes could take the mind to be thinking substance lacking extension yet claim that it is somehow attached to the body, given that anything joined to a body must itself be extended (O III (DM) 399b-401a; R 584-590). Descartes's answer is that he does not take mind and body to be attached, which response immediately invites Princess Elisabeth's puzzle.