It is obvious that two contingent statements, each of which denies the existence of something, can be inconsistent with one another: for example, ‘There are no non-black ravens, and there is at least one raven’, and ‘There are no black ravens’. But it is also obvious that these two statements are inconsistent only because one of them, as well as denying the existence of something, asserts the existence of something. The mere denials of existence, ‘There are no non-black ravens’ and (...) ‘There are no black ravens’, are consistent with one another. Indeed, it must hold quite generally that two contingent statements cannot be inconsistent, where each is a mere denial of existence in the sense that it denies existence and does not also assert existence. For in order to be inconsistent with a mere denial of existence, a second statement must assert existence, whatever else it may do; and if it asserts existence, it is not itself a mere denial of existence. (shrink)

One of the difficulties with which scientific endeavour is fraught is that of maintaining detachment. The scientist's interest in his work will lead him to formulate hypotheses and the hypotheses will lead him to expectations about future observations. Is disinterested investigation then possible? Surely the very formulation of a hypothesis engenders a paternal affection and a desire to preserve it. Knowing this, however, the scientist is able to guard against his expectations influencing his observations, defending thus both his objectivity and (...) his honour. But in cases where discriminations are exceptionally difficult to make, then here perhaps, in spite of fore-knowledge of the danger, and in spite of all precautions, an expectation may influence a judgement. (shrink)

One task of logic, Peirce held, is to classify arguments so as to determine the validity of each kind. His own classification is interesting because it includes a novel type of argument in addition to the two traditionally recognized types. It is the purpose of this paper to discuss what Peirce thought to be sufficiently distinctive about abduction to warrant calling it a new kind of argument. But since one finds in his writings on abduction a number of different views (...) it is first necessary to make a few remarks concerning the unity of Peirce's thought. (shrink)

Professor Karl Popper has had a great deal to endure: “expositions” of his ideas which were mere travesties, “refutations” which he had already answered, by anticipation, or which entirely missed the point at issue. One can easily understand why, when he came to publish an English translation of his Logik der Forschung, he decided to keep to the original text; it should at last be clear exactly what he had—and had not—said in 1934. Yet his thinking had by no means (...) stood still since that time; quite naturally, too, he wished to emphasize as much. (shrink)

When I was pondering what I should write about Lakatos in this article, I ran into what seemed an insuperable difficulty. On one hand I thought that part of my job should be to give a portrait of Lakatos' personal manner. This would be informative from the point of view of history of thought, as it would help people read his works with greater understanding. And it would be interesting, if I succeeded at all: everyone who knew Lakatos would agree (...) that he was one of the most remarkable people they had met. On the other hand memorial essays tend to give portraits whic are all sweetness and light. But such a portrait of Lakatos would not b a portrait of Lakatos. Everyone has his dark and his light side; sometimes we see one, occasionalley the other. But in Lakatos both were simultaneously and brilliantly displayed at every instant. (shrink)

First, we consider an argument due to Popper for maximal strength in choice of logic. We dispute this argument, taking a lead from some remarks by Susan Haack; but we defend a set of contrary considerations for minimal strength in logic. Finally, we consider the objection that Popper presupposes the distinctness of logic from science. We conclude from this that all claims to logical truth may be in equal epistemological trouble.

For over two decades, something akin to a scientific revolution in philosophy of science has been taking place. So, at any rate, claims Harold I. Brown, in his book Perception, Theory and Commitment: The New Philosophy of Science, in which he chronicles and defends the demise of logical empiricism and offers a new philosophy of science in its stead. The new philosophy of science, drawing on the work of Kuhn, Toulmin, Hanson, Lakatos, Polanyi, and others, but effectively structured, enhanced, and (...) defended by Brown, replaces logical empiricism's fundamental presuppositions of Principia logic and observation-based empiricism with a new approach which emphasizes the theory-ladenness of perception, the unavoidability of paradigmatic presuppositions, conceptual change and scientific revolutions, dialectic (as opposed to algorithmic) reasoning as the model of rational thinking in science, and a sharp rejection of the discovery/justification distinction. Brown develops a new epistemology of science to complement and underlie the new philosophy of science, including alternative conceptions of rationality, scientific knowledge, truth, objectivity, and relativism. Later in this essay I will attempt to recount, and bring to light some flaws in, both the new philosophy and the new epistemology of science Brown defends. First, however, it will be helpful to follow Brown's account of the nature and failings of the logical empiricist research program. (shrink)