Descartes' metaphysical doubts in the Third and Fifth Meditations present a scenario like this:it is possible that I (the Meditator) am so imperfect as to be deceived by my author (i.e.,an omnipotent God/Deceiver) in the matters which I think I perceive clearly and distinctly.The metaphysical doubts attempt to cast doubt on beliefs based on present or recollected clear and distinct perceptions.This paper clarifies the intension of the metaphysical doubts by answering the question of how an omnipotent God/Deceiver might exercise a deceptive influence on clear and distinct perception.My analysis shows:(1) the memory interpretation and the retrospective interpretation to be implausible;(2) the incoherence interpretation to be ill-founded,though its conclusion is partly right,such that we should accept a weaker version of it;(3) the misrepresentation interpretation,the defective-origin interpretation,the truth-value variation interpretation and the radical interpretation to be plausible;(4) all of these credible interpretations to be compatible with each other as well.