  To meet this challenge, Descartes must explain how he “bridges” the inferential gap between thought and reality. The principle of clear and distinct perception is intended to do just that. According to this principle, for which he argues in the Fourth Meditation, whatever one clearly and distinctly perceives or understands is true — true not just of ideas but of things in the real world represented by those ideas. Thus, Descartes’ commitment to the principle of clear and distinct perception allows him to elude another objection that had haunted Anselm’s version of the argument.