In the novel Stranger in a Strange Land, Robert Heinlein invented the concept of the Fair Witness. A Fair Witness could report everything that they observed, but would never render any opinion on what they had observed. To use Descartes' example, they would report that they saw figures wearing hats and coats through the open window, nothing more (Descartes 32). Yet Descartes’ doubt in Meditation #1 is more profound than that of a Fair Witness. This arises due to his emphasis on deductive logic, rather than induction.

While deductive logic can demonstrate proof, opposed to probability-based induction, a flaw in ones' premises will result in a valid argument – but a false result. In Meditations, Descartes corrects for this weakness by systematically examining all possible premises. Recognizing that judging all possible premises is an endless task, he cuts to fundamentals. He discards entire classes of premises, such as sensory input, if there is any possibility that a premise in that class may be deceptive. This practice of “hyperbolic doubt” appears to be an excellent method of ensuring both provable and true statements using deductive logic.

Indeed, Descartes' goal in Meditations is to find true, absolute knowledge – including knowledge of God (Descartes 2). Descartes even argues from Scripture that “everything that can be known about God can be shown by reasons drawn exclusively from our own mind” (Descartes 2). This assertion neatly sidesteps Thomas Paine's later categories of "revelation" and "hearsay" by asserting that God is knowable by man without supernatural intervention.

Hyperbolic doubt superficially resembles modern skepticism in its questioning of accepted tenets; Neither will be satisfied by mere conjecture or force of will. The differences, however, are fundamental. Modern skepticism is based on induction, requiring evidence instead of the deductive proof Descartes employs. Further, modern skepticism, most notably in the example of the Skeptics Society, is destructive in nature. That is, modern skepticism does not create proof or theories – it only demonstrates the falsity of a proposition. In contrast, Descartes’ methodology is constructive in nature. While it begins in doubt, it is a tool used with the express intent of creating a proven body of knowledge, not destroying it.