 Frankfurt thinks that Descartes’ novel plan involves arguing that our best rational efforts show that our best rational efforts are logically consistent: it is “an attempt to show that there are no good reasons for believing that reason is unreliable – that the mistrust of reason is not supported by reason and that it is accordingly irrational” (1970, 175). Frankfurt adds that “the conception of truth involved in [Descartes’] question about the truth of what is clearly and distinctly perceived is, in other words, a conception of coherence rather than of correspondence” (1970, 170).