Many of the things that we try to explain, in both our common sense and our scientific engagement with the world, are capable of being explained more or less finely: that is, with greater or lesser attention to the detail of the producing mechanism. A natural assumption, pervasive if not always explicit, is that other things being equal, the more finegrained an explanation, the better. Thus, Jon Elster, who also thinks there are instrumental reasons for wanting a more fine-grained explanation, assumes that in any case the mere fact of getting nearer the detail of production makes such an explanation intrinsically superior: “a more detailed explanation is also an end in itself” (Elster 1985, p. 5). Michael Taylor (1988, p. 96) agrees: “A good explanation should be, amongst other things, as fine-grained as possible.”

Many recent developments in artificial intelligence (AI) research are relevant for traditional issues in the philosophy of science. One of the developments in AI research we want to focus on in this article is diagnostic reasoning, which we consider to be of interest for the theory of explanation in general and for an understanding of explanatory arguments in economic science in particular. Usually, explanation is primarily discussed in terms of deductive inferences in classical logic. However, in recent AI research it is observed that a diagnostic explanation is actually quite different from deductive reasoning (see, for example, Reiter, 1987). In diagnostic reasoning the emphasis is on restoring consistency rather than on deduction. Intuitively speaking, the problem diagnostic reasoning is concerned with is the following. Consider a description of a system in which the normal behavior of the system is characterized and an observation that conflicts with this normal behavior. The diagnostic problem is to determine which of the components of the system can, when assumed to be functioning abnormally, account for the conflicting observation. A diagnosis is a set of allegedly malfunctioning components that can be used to restore the consistency of the system description and the observation. In this article, this kind of reasoning is formalized and we show its importance for the theory of explanation. We will show how the diagnosis nondeductively explains the discrepancy between the observed and the correct system behavior. The article also shows the relevance of the subject for real scientific arguments by showing that examples of diagnostic reasoning can be found in Friedman's Theory of the Consumption Function (1957). Moreover, it places the philosophical implications of diagnostic reasoning in the context of Mill's aprioristic methodology.

It is widely agreed that the concept of general equilibrium and, in particular, general equilibrium existence proofs play a central role within the neoclassical approach to economic theory. There is much less agreement, however, on the concepts of general equilibrium and of neoclassical economic theory themselves.

Theoretical works in economics usually have a core consisting of proofs that a “model-economy” has certain properties. The economist constructs a model that can be looked on as a description of an economy, and then proves that certain relations hold in this economy and/or that certain relations in this economy depend on certain specific characteristics. The model-economy is usually described as simplified or idealized.

Let me make it clear from the outset that my main point is not either of the following: one, that there should be more women economists and research on “women's issues” (though I think there should be), or two, that women as a class do, or should do, economics in a manner different from men (a position with which I disagree). My argument is different and has to do with trying to gain an understanding of how a certain way of thinking about gender and a certain way of thinking about economics have become intertwined through metaphor – with detrimental results – and how a richer conception of human understanding and human identity could broaden and improve the field of economics for both female and male practitioners.

When does self-interest counsel cooperation? This question pertains both to the labile behaviors produced by rational deliberation and to the more instinctive and fixed behaviors produced by natural selection. In both cases, a standard starting point for the investigation is the one-shot prisoners' dilemma. In this game, each player has the option of producing one or the other of two behaviors (labeled “cooperate” and “defect”). The pay-offs to the row player are as follows:

This article is concerned with the selection of an appropriate model of choice to underlie Rawls' (1971) two principles of justice. Rawls' first principle of justice states that basic liberty is not to be sacrificed for other objectives, including wealth. His second principle of justice suggests that even a minute decrease in the well-being of the least prosperous classes should not be accepted in exchange for an increase, no matter how large, in the well-being of more well-to-do citizens.

In their article “Roemer's ‘General’ Theory of Exploitation is a Special Case: The Limits of Walrasian Marxism,” Devine and Dymski portray me as some sort of Walrasian automaton who believes that phenomena that are not easily modelled using the Walrasian model of perfect competition do not exist. Their criticism of my theory assumes that I was attempting to model capitalism in its entirety, a task that, I agree, I failed to do. I did not propose a theory of accumulation, or of technological change, or of the methods by which capitalists maintain their ideological hegemony over workers, or of the methods by which they extract labor from labor power at the point of production. I was not, in short, trying to write an alternative to Das Kapital. My General Theory of Exploitation and Class (GTEC), as its Introduction explained, was an attempt at understanding the root causes of exploitation and class, so as to better understand how class formation and exploitation might occur in postcapitalist societies. To this end, I adopted a well-known scientific method: strip away many real aspects of the thing under study down to a minimal skeleton and see how many phenomena descriptive of the real thing one can generate. Then add more real aspects of the thing to the model, and see how much more one can generate.

John Roemer's comment (1992) succinctly summarizes the logical structure of his own theory of capitalist exploitation, but misunderstands the main points of our critique. He reduces his argument to two propositions. The first is an “empirical proposition”about the “root causes of exploitation”: X + Y →Z, where X is the existence of differential ownership of means of production (DOPA), Y is coercion in the labor process, and Z is the capitalist class structure and exploitation. The second is the strictly theoretical proposition X + not-Y -”Z, the truth of which he demonstrates, given most of the assumptions of a Walrasian economic model. He concludes that these two propositions, taken together, demonstrate the primacy of DOPA in explaining capitalist class relations. This much is true – subject to the various limitations we have indicated in our article – but only within the restricted confines of a Walrasian framework. This purely theoretical conclusion has no force as an empirical conclusion: this is the point at which Roemer's interpretation goes awry. For obviously, DOPA is a crucial element of empirical reality. But because Roemer's Walrasian framework precludes other equally crucial elements of empirical reality (which are also conceptually central to Marxian discourse), an irreducible distance remains therein between the theoretical and the empirical.