INTRODUCTION The present volume unites contributions by the leading figure of the Vienna Circle and by two of his closest assoCiates, contributions that deal with an area of thought represented, indeed, in this Collection but certainly not the central one in the common picture ofthe Circle's activities. It is no accident that an interest in ethics and the philosophy of action was particularly marked in what Neurath was apt to call the right wing of the Circle. For them, as for Wittgenstein (the respected mentorofSchlickandWaismanninparticular), theadvancetobehoped for in philosophy consisted not solely in freeing natural science from a confused sense of dependence on speculative metaphysics but also in seeingthatotherareasoflanguageandaction hadto bethoughtaboutin theirownterms, whichwereneitherthoseofnaturalsciencenorthoseof philosophy as traditionally conceived. The scepticismofSchlick about theprogrammeofUnifiedSciencewaswellknown: EinheizwissenschaJt he called it, as it might be 'boozified science'. And in sober truth the programme sometimes masked a left-wing set of values taken (surely illogically) for granted, though the membersofthe Circle entertained a wide range ofpolitical views. Schlick's own contribution to the present volume is a section from thenotesforoneofhisfinal lectureseries, forsightofwhich wewarmly thanktheonlysurvivingcontributortoourvolume, DrJosephSchachter: Schlick'sgrandsonDra. M. H. vandeVeldehaskindlyconsentedtotheir publication. This section poses the problem we have outlined: there are questionsandaneedforclarificationinethics, butthesenomoredemand a metaphysical solution than does a similar situation in epistemology. Here, as in his earlier Problems of Ethics, l Schlick sets his face against thewholeprocess, mostobviousin Kant, ofmakingtheconceptofvalue absolute. One might say that for Schlick there is no unhypothetical imperative.

a priori, and what is more, to a rejection based ultimately on a posteriori findings; in other words, the "pure" science of nature in Kant's sense of the term had proved to be, not only not pure, but even false. As for logic and mathematics, the decisive works of Frege, Russell, and White head suggested two conclusions: first, that it was possible to construct mathematics on the basis of logic (logicism), and secondly, that logical propositions had an irrevocably analytic status. But within the frame work of logicism, the status of logical propositions is passed on to mathematical ones, and mathematical propositions are therefore also conceived of as analytic. All this creates a situation where the existential presupposition contained in the Kantian question about the possibility of judgements that are both synthetic and a priori must, it seems, be rejected as false. But to drop this presupposition is, at the same time, to strike at the very core of Kant's programme of putting the natural sciences on a philosophical foundation. The failure of the modern attempt to do so suggests at the same time a reversal of the relationship between philosophy and the individual sciences: it is not the task of philosophy to meddle with the foundations of the individual sciences; being the less successful discipline, its task is rather to seek guidance from the principles of rationality operative in the individual sciences."

INTRODUCTION The present volume unites contributions by the leading figure of the Vienna Circle and by two of his closest assoCiates, contributions that deal with an area of thought represented, indeed, in this Collection but certainly not the central one in the common picture ofthe Circle's activities. It is no accident that an interest in ethics and the philosophy of action was particularly marked in what Neurath was apt to call the right wing of the Circle. For them, as for Wittgenstein (the respected mentorofSchlickandWaismanninparticular), theadvancetobehoped for in philosophy consisted not solely in freeing natural science from a confused sense of dependence on speculative metaphysics but also in seeingthatotherareasoflanguageandaction hadto bethoughtaboutin theirownterms, whichwereneitherthoseofnaturalsciencenorthoseof philosophy as traditionally conceived. The scepticismofSchlick about theprogrammeofUnifiedSciencewaswellknown: EinheizwissenschaJt he called it, as it might be 'boozified science'. And in sober truth the programme sometimes masked a left-wing set of values taken (surely illogically) for granted, though the membersofthe Circle entertained a wide range ofpolitical views. Schlick's own contribution to the present volume is a section from thenotesforoneofhisfinal lectureseries, forsightofwhich wewarmly thanktheonlysurvivingcontributortoourvolume, DrJosephSchachter: Schlick'sgrandsonDra. M. H. vandeVeldehaskindlyconsentedtotheir publication. This section poses the problem we have outlined: there are questionsandaneedforclarificationinethics, butthesenomoredemand a metaphysical solution than does a similar situation in epistemology. Here, as in his earlier Problems of Ethics, l Schlick sets his face against thewholeprocess, mostobviousin Kant, ofmakingtheconceptofvalue absolute. One might say that for Schlick there is no unhypothetical imperative.

a priori, and what is more, to a rejection based ultimately on a posteriori findings; in other words, the "pure" science of nature in Kant's sense of the term had proved to be, not only not pure, but even false. As for logic and mathematics, the decisive works of Frege, Russell, and White head suggested two conclusions: first, that it was possible to construct mathematics on the basis of logic (logicism), and secondly, that logical propositions had an irrevocably analytic status. But within the frame work of logicism, the status of logical propositions is passed on to mathematical ones, and mathematical propositions are therefore also conceived of as analytic. All this creates a situation where the existential presupposition contained in the Kantian question about the possibility of judgements that are both synthetic and a priori must, it seems, be rejected as false. But to drop this presupposition is, at the same time, to strike at the very core of Kant's programme of putting the natural sciences on a philosophical foundation. The failure of the modern attempt to do so suggests at the same time a reversal of the relationship between philosophy and the individual sciences: it is not the task of philosophy to meddle with the foundations of the individual sciences; being the less successful discipline, its task is rather to seek guidance from the principles of rationality operative in the individual sciences."