Abstract
It has been the author's purpose to compare the conceptions of Descartes and Wittgenstein with regard to the certainty which is supposed to be the basis of human knowledge. Three types of certainty are distinguished : practical, rational and metaphysical certainty. Special attention has been given to both philosophers' opinions on the certainty of the ego cogito and of God. The historically interesting result of the study is that the ideas of Descartes and Wittgenstein in re the three types of certainty, and the fundamental meaning of the cogito and of God, converge to a far greater extent than is commonly supposed, and that the main difference between their contentions lies in an unexpected area, their divergent ideas about the problem of the will. The article's contribution to systematic philosophy may lie in the emphasis on the difference between certainty and truth which can be found in the philosophies of both Descartes and Wittgenstein, and which is shown to be essential for the nature of human knowledge, as a longing for truth which, in view of man's finite possibilites, cannot be reached