Descartes and Methodological doubt

The common meaning of 'doubt' entails an unwillingness to act upon its object. Thus, the distinction of this meaning from Cartesian 'doubt' is clear--while Descartes may be able to doubt that a fire that seems to be engulfing the room in which is meditating actually exists, it seems unlikely that he would hesitate for a second to act upon his perception of it. The appropriateness of Sartre's characterization of Cartesian doubt as 'methodological' is evident when Descartes asserts not 'I doubt', but 'I can doubt'. His usage of the latter expression frequently seems to imply that 'I can doubt X' means 'I can construct an hypothesis that explains how I seem to perceive X, but something other than X, e. g. a dream, an hallucination, is the cause of the seeming perception'. However, in at least one other instance, 'I can doubt' instead means 'it is not contradictory for me to doubt X'. That instance arises when he asserts that he cannot doubt that he doubts X. However, that application of the Law of Contradiction seems, at minimum, to be misapplied. For, the question is whether or not he can doubt that he methodologically doubts X, so it is a question of whether or not he can doubt that he CAN doubt X, and not that he DOES doubt X. Now, on either definition of 'doubt', it seems unarguably contradictory to assert both 'I cannot doubt X' and 'I can doubt X'. But, in contrast, 'I can doubt that I doubt X' does not syntactically contradict 'I can doubt X', and indeed, the experience of dreaming that one is dreaming verifies it. So, Descartes' presentation suggests that he does not consider that his introduction of methodological doubt also calls into question traditional Logic.