Intervening and Letting Go: On the Adequacy of Equilibrium Causal Models

Causal representations are distinguished from non-causal ones by their ability to predict the results of interventions. This widely-accepted view suggests the following adequacy condition for causal models: a causal model is adequate only if it does not contain variables regarding which it makes systematically false predictions about the results of interventions. Here I argue that this condition should be rejected. For a class of equilibrium systems, there will be two incompatible causal models depending on whether one intervenes upon a certain variable to fix its value, or ‘lets go’ of the variable and allows it to vary. The latter model will fail to predict the result of interventions on the let-go-of variable. I argue that there is no basis for preferring one of these models to the other, and thus that models failing to predict interventions on particular variables can be just as adequate as those making no such false predictions. This undermines a key argument (Dash in Caveats for causal reasoning with equilibrium models. University of Pittsburgh. PhD thesis, 2003) against relying upon causal models inferred from equilibrium data.

Perception, Reliability, and Other Minds

It has been suggested that we can come by our knowledge of what others think and feel through perception. The idea has been worked out in different ways by different philosophers. In this chapter I consider the perceptual account proposed by Fred Dretske. In section one I outline Dretske’s account, and highlight a particular feature of it. In section two I set out an adequacy condition for any account that proposes to be an account of our mental life. In section three I consider Dretske’s account in the light of this adequacy condition and argue that Dretske’s account does not meet this condition. I conclude that while Dretske holds that we get our knowledge of other minds in much the same way that we get our knowledge of bodies in the world around us, I argue that the account cannot be extended to give us knowledge of other minds because there is a crucial asymmetry here that must be acknowledged.

Social Justicitis

This chapter examines what it calls “social justicitis”—a strongly negative, even allergic, reaction to the ideal of social or distributive justice. Social justicitis is a malady from which many defenders of private economic liberty suffer. For libertarians, arguments on behalf of social justice may be as threatening as a bee sting is to some people. In the case of classical liberals, social justicitis arises as an adverse reaction to talk about social justice at the level of public policy. The chapter first considers the notion of distributional adequacy condition from the perspective of classical liberalism and libertarianism before discussing the arguments of classical liberals and libertarians regarding property and the poor. It also explores F. A. Hayek's critique of social justice and the implications of his theory of spontaneous order with respect to distributional ideals.

Über Die Sogenannte Normativität Der Bedeutung

This paper aims to demonstrate that it is by no means clear whether the thesis that meaning is intrinsically normative can be justifi ed. Therefore, we should not regard the explanation or the grasp of the normativity of meaning as an adequacy condition of a theory of meaning — as some philosophers do. In the first part of the paper, I distinguish four intuitive kinds of normativity of meaning. After that, I focus on the question what sorts of normativity can be distinguished in general. I discuss the advantages and problems of a common characterization of normativity, adopted by Schnädelbach and von Wright, and I defend a certain modifi ed version of this characterization. In the third part of the paper, I apply this modifi ed characterization to the four kinds of normativity of meaning distinguished earlier, and I show that only one of the four is compatible with the thesis that meaning is an intrinsically normative concept. In the last part of the paper, I focus on the semantic relations between meaning and use, and I reject some common forms of reducing facts about meaning to facts about use.

A Logically Justified Model of Computation I

The aim of this paper is to provide a general explanation of the “algorithmic content” of proofs, according to a point of view adequate to computer science. Differently from the more usual attitude of program synthesis, where the “algorithmic content” is captured by translating proofs into standard algorithmic languages, here we propose a “direct” interpretation of “proofs as programs”. To do this, a clear explanation is needed of what is to be meant by “proof-execution”, a concept which must generalize the usual “program-execution”. In the first part of the paper we discuss the general conditions to be satisfied by the executions of proofs and consider, as a first example of proof-execution, Prawitz’s normalization. According to our analysis, simple normalization is not fully adequate to the goals of the theory of programs: so, in the second section we present an execution-procedure based on ideas more oriented to computer science than Prawitz’s. We provide a soundness theorem which states that our executions satisfy an appropriate adequacy condition, and discuss the sense according to which our “proof-algorithms” inherently involve parallelism and non determinism. The Properties of our computation model are analyzed and also a completeness theorem involving a notion of “uniform evaluation” of open formulas is stated. Finally, an “algorithmic completeness” theorem is given, which essentially states that every flow-chart program proved to be totally correct can be simulated by an appropriate “purely logical proof”.