What is tacit knowledge? What role does it play in working life? What does this imply for our understanding, say, of the implications of new technology such as Expert Systems for working life? What do philosophers of science have to learn from working life studies? These have been the principle issues which preoccupied me in the course of my stay at Arbetslivscentrum. In what follows I propose to answer these questions, at least in a preliminary way, with a view to elucidating the perspective of the project "Utbildning-Arbete-Teknik" with which I have been associated. This amounts to clarifying a number of issues about which there is a good deal of confusion relating to the crucial notion of tacit knowledge, the ways in which theory of knowledge (a term I much dislike but employ for want of a better one) can clarify our understanding of working life, as well as the role working life studies can play in the development of the theory of knowledge. It is, then, at once a compilation of the ideas which have been most central to my work in the Center as well as a statement of what I take back to the academic world from my experiences at the Center. It is hardly intended to be comprehensive; rather it is a sketch of what I, as a philosopher, take to be the most challenging and exciting notions that I have encountered confronting the "real world" of work.