 These passages (and others) suggest an account wherein doubt is the contrast of certainty. As my certainty increases, my doubt decreases; conversely, as my doubt increases, my certainty decreases. The requirement that knowledge is to be based in complete, or perfect certainty, thus amounts to requiring a complete inability to doubt one’s convictions – an utter indubitability. This conception of the relationship between certainty and doubt helps underwrite Descartes’ methodical emphasis on doubt, the so-called ‘method of doubt’ (discussed in  Section 2).