Being and Time raises the problem of "authenticity," that is, the potentiality or otherwise for mortal "Dasein" to exist "fully" enough that it might actually understand being. Heidegger is clear throughout the book that nothing makes certain that "Dasein" is capable of this understanding. Finally, this question of the authenticity of individual "Dasein" cannot be separated from the "historicality" of "Dasein". On the one hand, "Dasein", as mortal, is "stretched along" between birth and death, and thrown into its world, that is, thrown into its "possibilities", possibilities which "Dasein" is charged with the task of assuming. On the other hand, "Dasein's" access to
Philosopher in Meditation and titling it "Philosopher in Contemplation" or "Philosopher with an Open Book". Yet the real credit for the attribution to Koninck should go to John C. Van Dyke, who wrote: "In fact, one may be heretical enough to think that someone like Koninck or Dou may have painted them..." The subject matter and details of the Koninck picture seem to have been directly inspired by a Rembrandt etching dated 1642 and representing "St. Jerome in a dark chamber" (Bartsch 105), which is the only other known work by Rembrandt that features a complete helical staircase. The traditional iconography of the