Conclusion: The Cartesian nightmare come true

No conclusions can be more agreeable to scepticism than such as make discoveries concerning the weakness and narrow limits of human reason and capacity. E VII/ii.59 This sceptical doubt, both with respect to reason and the senses, is a malady, which can never be radically cur'd, but must return upon us every moment, however we may chace it away, and sometimes may seem entirely free from it. T 218 Errors in religion are dangerous; those in philosophy only ridiculous. T 272 In the concluding section of An Enquiry Concerning Human Understanding – “Of the Academical or Sceptical Philosophy” – Hume offered the following description of Cartesian skepticism: There is a species of scepticism, antecedent to all study and philosophy, which is much inculcated by Des Cartes and others, as a sovereign preservative against error and precipitate judgment. It recommends an universal doubt, not only of all our former opinions and principles, but also of our very faculties; of whose veracity, say they, we must assure ourselves, by a chain of reasoning, deduced from some original principle, which cannot possibly be fallacious or deceitful. But neither is there any such original principle, which has a prerogative above others, that are self-evident and convincing: or if there were, could we advance a step beyond it, but by the use of those very faculties, of which we are supposed to be already diffident. ( E XII/i.116) Cartesian doubt, as Hume understood it, has at its focal point human nature itself (“our very faculties”).