When Seeing is not Believing

Notre Dame Journal of Formal Logic, 1997

David Lewis has argued that impossible worlds are nonsense: if there were such worlds, one would have to distinguish between the truths about their contradictory goings-on and contradictory falsehoods about them; and this—Lewis argues—is preposterous. In this paper I examine a way of resisting this argument by giving up the assumption that ‘in so-and-so world’ is a restricting modifier which passes through the truth-functional connectives The outcome is a sort of subvaluational semantics which makes a contradiction ‘A & ~A’ false even when both ‘A’ and ‘~A’ are true, just as supervaluational semantics makes a tautology ‘A v ~A’ true even when neither ‘A’ nor ‘~A’ are. Connections with discussive logics and complications of the account are discussed, and some general morals are drawn.

Lucas and Redhead ([2007]) announce that they will defend the views of Redhead ([2004]) against the argument by Panu Raatikainen ([2005]). They certainly re-state the main claims of Redhead ([2004]), but they do not give any real arguments in their favour, and do not provide anything that would save Redhead's argument from the serious problems pointed out in ). Instead, Lucas and Redhead make a number of seemingly irrelevant points, perhaps indicating a failure to understand the logico-mathematical points at issue.

Philosophical Studies, 2010

In a recent article M. Colyvan has argued that Quinean forms of scientific realism are faced with an unexpected upshot. Realism concerning a given class of entities, along with this route to realism, can be vindicated by running an indispensability argument to the effect that the entities postulated by our best scientific theories exist. Colyvan observes that among our best scientific theories some are inconsistent, and so concludes that, by resorting to the very same argument, we may incur a commitment to inconsistent entities. Colyvan’s argument could be interpreted, and in part is presented, as a reductio of Quinean scientific realism; yet, Colyvan in the end manifests some willingness to bite the bullet, and provides some reasons why we shouldn’t feel too uncomfortable with those entities. In this paper we wish to indicate a way out to the scientific realist, by arguing that no indispensability argument of the kind suggested by Colyvan is actually available. To begin with, in order to run such an indispensability argument we should be justified in believing that an inconsistent theory is true; yet, in so far as the logic we accept is a consistent one it is arguable that our epistemic predicament could not be possibly one in which we are justified in so believing. Moreover, also if our logic admitted true contradictions, as Dialetheism does, it is arguable that Colyvan’s indispensability argument could not rest on a true premise. As we will try to show, dialetheists do not admit true contradictions for cheap: they do so just as a way out of paradox, namely whenever we are second-level ignorant as to the metaphysical possibility of evidence breaking the parity among two or more inconsistent claims; Colyvan’s examples, however, are not of this nature. So, even under the generous assumption that Dialetheism is true, we will conclude that Colyvan’s argument doesn’t achieve its surprising conclusion.

2008

In this paper, I investigate the logical relation between two claims: (1) observations are theory-laden 1 and (2) there is no empirical common ground upon which to evaluate successive scientific theories that belong to different paradigms. I, first, construct an argument where (1) is the main premise and (2) is the conclusion. I argue that the term "theory-laden" has three distinct senses: semantic, psychological and epistemic. If 'theory-laden' is understood in either epistemic or psychological senses, then the conclusion becomes a claim about people. If incommensurability is to be a claim about theories, then 'theory-laden' in the main premise should be understood in the semantic sense. I, then, argue that there is a further distinction to be drawn between the absolute and relative senses of theory-laden. The relative sense of theory-laden allows observations that are relatively neutral between the theories under examination. I then conclude that the argument from theory-ladenness only shows that foundational empiricism is not a tenable philosophical position, but it fails to show that no empirical test can decide between successive theories that belong to different paradigms. 1 First things are first. Let's remember Dretske's distinction between "seeing as" and "seeing that" (1969). "Seeing as" is to perceive, under appropriate conditions, whatever observable properties an object has, without passing any judgment on what these properties are. However, "seeing that" involves describing what one sees. For example, most animals that have eyes similar to ours see objects-trees, other animals, etc. However, they don't see, for example, that what they are looking at is a tree. Only "seeing that" kind of observations, whether in the sense of psychological, epistemological or semantic, are theory-laden. See also Bird (2000, 97-148) where he makes similar distinctions and based on these distinctions he argues against this premise that both Hanson and Kuhn defended. Bird (2000, 122) argues that theory-dependence of perception is weaker than Hanson and Kuhn thought and that for this reason it does not establish the conclusion that there are no common observations to successive paradigms. In this paper, though, I will grant that the premise is true and then see what follows from it. See also Anna Estancy (2001) on theory-ladenness of observation and the neutrality of observation. She presents an account of theory-laden in the light of new developments in cognitive science and argues that theory-ladenness of observation does not undermine the objectivity of science. However, these arguments don't focus on the logical relationship between this premise and the conclusion presented in the above argument. See also William F. Brewer and Bruce L. Lambert (2001) for a similar kind of account.

Foundations of Science, 1998

ABSTRACT. We put forward the hypothesis that there exist three basic attitudes towards inconsistencies within world views: (1) The inconsistency is tolerated temporarily and is viewed as an expression of a temporary lack of knowledge due to an incomplete or wrong theory. The resolution of ...