Husserlian variation, Bergsonian intuition and Peircean abduction are contrasted as methodological responses to the traditional philosophical problem of deriving knowledge of universals from singulars. Each method implies a correspondingly different view of the generation of the variations from which knowledge is derived. To make sense of the latter differences, and to distinguish the different sorts of variation sought by philosophers and scientists, a distinction between extensive, intensive, and abductive-intensive variation is introduced. The link between philosophical method and the generation of (...) variation is used to illuminate different philosophical conceptions of nature and nature's relation to meaning and sense. (shrink)