Apply the test of true and false to problems themselves. Condemn false problems and reconcile truth and creation at the level of problems.

--- Gilles Deleuze (1991:15), Bergsonism, trans. H.Tomlinson and B.Habberjam, New York, Zone Books, quoted by Elie During in "'A History of Problems' : Bergson and the French Epistemological Tradition," Journal of the British Society for Phenomenology, vol.35, n°1, January 2004, http://ciepfc.rhapsodyk.net/article.php3?id_article=65

As Deleuze reportedly goes on : 'While it is relatively easy to define the true and the false in relation to solutions whose problems have already been stated, it seems much more difficult to say in what the true and the false consist when applied to the process of stating problems.' (ibid., 16).