 If Descartes holds that eternal truths are necessary in any robust sense, Frankfurt’s view has an obvious drawback. It also suffers from the problem that it [Frankfurt’s view] cannot be formulated without supposing that Descartes allows that there is a human perspective from which eternal truths can be seen to be non-necessary, but an important component of Frankfurt’s view is the thesis that Descartes thinks that it is part of the structure of a human mind to regard eternal truths as wholly necessary.