In this paper, I shall be discussing Husserl's and Heidegger's views on the role that human activity plays in the constitution of the world. While the basic idea in Husserl's phenomenology is that we constitute the world through our consciousness, Heidegger's main contribution to philosophy, it seems to me, is to focus attention on the idea that all human activity, all our ways of relating to the world, to one another and to ourselves, contribute to constituting the world.