The historical impact of the six meditations has been divided. The first two meditations, which employed the skeptical methodic doubt and concluded that only the ego and its thoughts are indubitable, have had a huge impact in the history of philosophy.[20] They are often considered as epoch-making for modernity, and an unavoidable first step for any modern philosophical thinking.[20][21]
Arthur David Smith, author of the Routledge Philosophy Guidebook to Husserl, claims that since Edmund Husserl usually refers only to "the first two" of the Meditations, therefore Husserl must have thought that they are the only part of Descartes' work with any philosophical importance at all.[20]