 These common words, finding oneself, world, occupying oneself, are now technical words in this new philosophy. One would be able to talk for a long time on each one of them, but I will limit myself to observe that this definition, “to live is to find oneself in a world”, like all the principal ideas in these lectures, is already in my published work. It is important to me to observe this, especially, with regard to the idea of existence, for which I claim chronological priority. For that very reason I am pleased to acknowledge that the person who has gone deepest into the analysis of life is the new German philosopher, Martin Heidegger.