Rationality and the tu quoque argument

The tu quoque argument is the argument that since in the end rationalism rests on an irrational choice of and commitment to rationality, rationalism is as irrational as any other commitment. Popper's and Polanyi's philosophies of science both accept the argument, and have on that account many similarities; yet Popper manages to remain a rationalist whereas Polanyi decided for an irrationalist version of rationalism. This is more marked in works of their respective followers, W. W. Bartley III and Thomas S. Kuhn. Bartley declares the rationalist's very openness to criticism open to criticism, in the hope of rendering Popper's critical rationalism quite comprehensive. Kuhn makes rationality depend on the existence of an accepted model for scientific research (paradigm), thus rendering Polanyi's view of the authority of scientific leadership a sine qua non for scientific progress. The question raised here is, in what sense is a rationalist committed to his rationality, or an irrationalist to his specific axiom ? The tradition views only the life‐long commitment as real. Viewing rationality as experimental open‐mindedness, we may consider a rationalist unable to retreat into any life‐long commitment — even commitment to science. In this way the logic of the tu quoque argument is made irrelevant: anyone able to face the choice between rationality and commitment is already beyond such a choice; it is one thing to be still naïve and another — and paradoxical — thing to return to one's naïveté.     

The pessimistic induction: a bad argument gone too far

In this paper, I consider the pessimistic induction construed as a deductive argument (specifically, reductio ad absurdum) and as an inductive argument (specifically, inductive generalization). I argue that both formulations of the pessimistic induction are fallacious. I also consider another possible interpretation of the pessimistic induction, namely, as pointing to counterexamples to the scientific realist’s thesis that success is a reliable mark of (approximate) truth. I argue that this interpretation of the pessimistic induction fails, too. If this is correct, then the pessimistic induction is an utter failure that should be abandoned by scientific anti-realists.     

Raising argument strength using negative evidence: a constraint on models of induction

Both intuitively, and according to similarity-based theories of induction, relevant evidence raises argument strength when it is positive and lowers it when it is negative. In three experiments, we tested the hypothesis that argument strength can actually increase when negative evidence is introduced. Two kinds of argument were compared through forced choice or sequential evaluation: single positive arguments (e.g., “Shostakovich’s music causes alpha waves in the brain; therefore, Bach’s music causes alpha waves in the brain”) and double mixed arguments (e.g., “Shostakovich’s music causes alpha waves in the brain, X’s music DOES NOT; therefore, Bach’s music causes alpha waves in the brain”). Negative evidence in the second premise lowered credence when it applied to an item X from the same subcategory (e.g., Haydn) and raised it when it applied to a different subcategory (e.g., AC/DC). The results constitute a new constraint on models of induction.     

Grounding and the indispensability argument

There has been much discussion of the indispensability argument for the existence of mathematical objects. In this paper I reconsider the debate by using the notion of grounding, or non-causal dependence. First of all, I investigate what proponents of the indispensability argument should say about the grounding of relations between physical objects and mathematical ones. This reveals some resources which nominalists are entitled to use. Making use of these resources, I present a neglected but promising response to the indispensability argument—a liberalized version of Field’s response—and I discuss its significance. I argue that if it succeeds, it provides a new refutation of the indispensability argument; and that, even if it fails, its failure may bolster some of the fictionalist responses to the indispensability argument already under discussion. In addition, I use grounding to reply to a recent challenge to these responses.     

The knowledge argument,the open question argument,and the moral problem

Someone who knew everything about the world’s physical nature could, apparently, suffer from ignorance about various aspects of conscious experience. Someone who knew everything about the world’s physical and mental nature could, apparently, suffer from moral ignorance. Does it follow that there are ways the world is, over and above the way it is physically or psychophysically? This paper defends a negative answer, based on a distinction between knowing the fact that p and knowing that p. This distinction is made intelligible by reference to criterial connections between the possession of moral or phenomenal knowledge, and the satisfaction of cognitively neutral conditions of desire and experiential history. The existence of such connections in the moral case makes for an efficient dissolution of the so-called moral problem.     

Lehrer and the consequence argument

The consequence argument of van Inwagen is widely regarded as the best argument for incompatibilism. Lewis??s response is praised by van Inwagen as the best compatibilist??s strategy but Lewis himself acknowledges that his strategy resembles that of Lehrer. A comparison will show that one can speak about Lehrer?CLewis strategy, although I think that Lewis??s variation is dialectically slightly stronger. The paper provides a response to some standard objections of incompatibilists to the Lehrer?CLewis reply.     

Truthmakers and the direct argument

The truthmaker literature has recently come to the consensus that the logic of truthmaking is distinct from classical propositional logic. This development has huge implications for the free will literature. Since free will and moral responsibility are primarily ontological concerns (and not semantic concerns) the logic of truthmaking ought to be central to the free will debate. I shall demonstrate that counterexamples to transfer principles employed in the direct argument occur precisely where a plausible logic of truthmaking diverges from classical logic. Further, restricted transfer principles (like the ones employed by McKenna, Stump, and Warfield) are as problematic as the original formulation of the direct argument.     

Motion and the affection argument

In the Metaphysical Foundations of Natural Science, Kant presents an argument for the centrality of <motion> to our concept <matter>. This argument has long been considered either irredeemably obscure or otherwise defective. In this paper I provide an interpretation which defends the argument’s validity and clarifies the sense in which it aims to show that <motion> is fundamental to our conception of matter.     

Biological motion shown backwards: the apparent-facing effect

We examined how showing a film backwards (reverse transformation) affects the visual perception of biological motion. Adults and 6-year-old children saw first a point-light quadruped moving normally as if on a treadmill, and then saw the same display in reverse transformation. For other groups the order of presentation was the opposite. Irrespective of the presentation mode (normal or reverse) and of the facing of the point-light figure (rightward or leftward), a pronounced apparent-facing effect was observed: the perceptual identification of a display was mainly determined by the apparent direction of locomotion. The findings suggest that in interpreting impoverished point-light biological-motion stimuli the visual system may neglect distortions caused by showing a film backwards. This property appears to be robust across perceptual development. Possible explanations of the apparent-facing effect are discussed.