Peirce on doubt

Ovi Magazine's "Charles Sanders Peirce and the Presuppositions of Science":

One of his early discoveries was that, despite Descartes’ cogito, scientific intelligences do not begin their activities in and intellectual vacuum. There are presuppositions of science and scientific method and they basically fall into two large classes: religion and common sense. Peirce speculated that scientific activity is based upon religion, whether or not the scientific intelligence is aware of it or not, because the ideals of that method presuppose a search for the truth about a reality not yet known. This idea of faith or basic beliefs being the base of science can be found in both Aquinas [sic] Summa and in Thomas Kuhn’s The Structure of Scientific Revolutions. Moreover, Peirce sees knowledge as a means of stabilizing our habitual behavior in response to doubt. [...]

Pierce rejects Descartes [sic] “paper doubt,” a doubt considered merely as an intellectual exercise, and sidesteps the whole issue of epistemological skepticism. His foundational, scientific metaphysics accordingly begins with phenomenology, the way things are presented to us in experience. He is particularly concerned with the difference between belief and doubt. Real doubt ensues when recalcitrant experience, which is not reflection, causes us to waver in our beliefs. A belief, as Peirce understands it, is not some kind of intellectual disposition to assent to a proposition, but a behavioral habit manifest in action. Therefore, when real doubt ensues it disrupts our usual behavioral patterns. Cartesian doubt, on the other hand, can make no difference to the way we act.

(Emphasis from original article...via Books, Inq.)