Thomas Baldwin, Nicholas Griffin and Peter Hylton have done much to show in what way the idealism of T.H. Green and F.H. Bradley was an important factor in the origin of British analytic philosophy and especially in the development of Moore's and Russell's thought. Baldwin's monograph on Moore, published in 1990, and the monographs of both Hylton and Griffin on Russell, published in 1990 and 1991, show not only that Russell and Moore had been idealistic philosophers in their youth, but also that idealistic themes influenced their later, realist philosophy. There need thus be no doubt about the influence of idealistic philosophy on the origin of British analytic philosophy. Those monographs leave open a question, though: Is the reaction towards idealism purely an immanent development of British philosophy, or were Moore and Russell influenced by other, less idealistic types of philosophy? In this paper I deal with this question by studying the early writings of Twardowski, on the one hand, and those of Moore and Russell in the period from ! 899 to 1903, on the other. It may be questioned whether the theories of Moore and Russell in that period can be characterized as analytic: they are not analytic in the sense in which we call Russell's "On Denoting" (1905) analytic in so far as "On Denoting" is a paradigm of analytic philosophy as critique of language. Taking a broader concept of analytic philosophy we may call their philosophies in that period analytic, however, because at that time Moore and Russell consider analysis a fruitful method in philosophy. For them, the analysis of thought is possible through the analysis of language or through the analysis of our acts and their objects. This notion of analysis does not set off analytic philosophy against phenomenology or descriptive psychology. My aim is to show that the transition from idealism to analytic philosophy was much smoother than is sometimes believed, because the transition was prepared by continental and British theories of the mind. These theories of the mind we find both in philosophy and in psychology two fields that at the end of the nineteenth century were not separate. My thesis is historical: my aim is to show that twentieth century, British analytic philosophy emerged from a much broader field of philosophies than sometimes is believed. Contemporary philosophy can profit from the ideas in this broader field from which analytic philosophy originated, for example, in the theory of wholes and parts, in the way we think that analysis might still be a fruitful method for philosophy, and