Online research in philosophy

Metaethical questions are typically held to be a priori , and therefore impervious to empirical evidence. Here I examine the metaethical claim that motive-internalism about belief (or belief-internalism), the position that moral beliefs are intrinsically motivating, is true. I argue that belief-internalists are faced with a dilemma. Either their formulation of internalism is so weak that it fails to be philosophically interesting, or it is a substantive claim but can be shown to be empirically false. I then provide evidence for the falsity of substantive belief-internalism. I describe a group of brain-damaged patients who sustain impairment in their moral sensibility: although they have normal moral beliefs and make moral judgments, they are not inclined to act in accordance with those beliefs and judgments. Thus, I argue that they are walking counterexamples to the substantive internalist claim. In addition to constraining our conception of moral reasoning, this argument stands as an example of how empirical evidence can be relevantly brought to bear on a philosophical question typically viewed to be a priori.

To evaluate Hume's thesis that causal claims are always empirical, I consider three kinds of causal statement: ?e1 caused e2 ?, ?e1 promoted e2 ?, and ?e1 would promote e2 ?. Restricting my attention to cases in which ?e1 occurred? and ?e2 occurred? are both empirical, I argue that Hume was right about the first two, but wrong about the third. Standard causal models of natural selection that have this third form are a priori mathematical truths. Some are obvious, others less so. Empirical work on natural selection takes the form of defending causal claims of the first two types. I provide biological examples that illustrate differences among these three kinds of causal claim.

Metaethical questions are typically held to be a priori, and therefore impervious to empirical evidence. Here I examine the metaethical claim that motive-internalism about belief (or belief-internalism), the position that moral beliefs are intrinsically motivating, is true. I argue that belief-internalists are faced with a dilemma. Either their formulation of internalism is so weak that it fails to be philosophically interesting, or it is a substantive claim but can be shown to be empirically false. I then provide evidence for the falsity of substantive belief-internalism. I describe a group of brain-damaged patients who sustain impairment in their moral sensibility: although they have normal moral beliefs and make moral judgments, they are not inclined to act in accordance with those beliefs and judgments. Thus, I argue that they are walking counterexamples to the substantive internalist claim. In addition to constraining our conception of moral reasoning, this argument stands as an example of how empirical evidence can be relevantly brought to bear on a philosophical question typically viewed to be a priori.

The major divide in contemporary epistemology is between those who embrace and those who reject a priori knowledge. Albert Casullo provides a systematic treatment of the primary epistemological issues associated with the controversy. By freeing the a priori from traditional assumptions about the nature of knowledge and justification, he offers a novel approach to resolving these issues which assigns a prominent role to empirical evidence. He concludes by arguing that traditional approaches to the a priori, which focus primarily on the concepts of necessity and analyticity, are misguided.

Scientific essentialism is the view that some necessities (e.g., water = H2O) can be known only with the aid of empirical science. The thesis of the paper is that scientific essentialism does not extend to the central questions of philosophy and that these questions can be answered a priori. The argument is that the evidence required for the defense of scientific essentialism (e.g., twin earth intuitions) is reliable only if the intuitions required by philosophy to answer its central questions is also reliable. Included is an outline of a modal reliabilist theory of basic evidence and a concept-possession account of the reliability of a priori intuition.

The paper argues that the use of epistemic terms, prominently “… knows” and even “… knows a priori/a posteriori” is context-sensitive along several dimensions. Besides the best known dimension of quality of evidence (lower quality for less demanding context, and higher one for more demanding), there is a dimension of depth (shallow justification for superficial evaluation, and deeper justification for deeper probing evaluation contexts). This claim is illustrated by context-dependent ascription of apriority and aposteriority. The argument proposed here focuses upon the status of propositions that are analytic in empirical concepts (like “Whales are animals”). It is a commonplace in epistemology that any analytic proposition (including e-analytic ones) is a priori. The paper claims that propositions analyzing empirical concepts are an interesting counterexample. It develops the following argument: Many such propositions have empirical counterparts that are expressed by the same form-of-words. (E.g., the form of words “Whales are mammals” can express both an e-analytic proposition and an empirical statement.) They normally derive from their empirical counterparts. Beliefs in such propositions, can be explicitly justified either a priori, by pointing out their conceptual, analytic status, or by reverting to their empirical counterparts. In contexts of very superficial evaluation, one may justify such an analytic belief in the first, conceptual way. In most contexts a belief in a proposition analyzing an empirical concept is being justified by appeal to its empirical counterparts. The empirical justification is normally taken as being ultimate. Empirical counterparts are derivationally deeper than the corresponding analytic propositions, and empirical justification is deeper than a priori one as well. Therefore, propositions analyzing empirical concepts are deeply a posteriori and superficially a priori.

The topic of a priori knowledge is approached through the theory of evidence. A shortcoming in traditional formulations of moderate rationalism and moderate empiricism is that they fail to explain why rational intuition and phenomenal experience count as basic sources of evidence. This explanatory gap is filled by modal reliabilism -- the theory that there is a qualified modal tie between basic sources of evidence and the truth. This tie to the truth is then explained by the theory of concept possession: this tie is a consequence of what, by definition, it is to possess (i.e., to understand) one’s concepts. A corollary of the overall account is that the a priori disciplines (logic, mathematics, philosophy) can be largely autonomous from the empirical sciences.

Frank Jackson has argued that only if we have a priori knowledge of the extension-fixers for many of our terms can we vindicate the methodological practice of relying on intuitions to decide between philosophical theories. While there has been much discussion of Jackson's claim that we have such knowledge, there has been comparatively little discussion of this most powerful argument for that claim. Here I defend an alternative explanation of our intuitions about possible cases, one that does not rely on a priori extension-fixers. This alternative explanation provides a vindication of our reliance on intuitions, while blocking Jackson's abductive argument for a priori semantic knowledge. In brief, I argue that we should regard our armchair intuitions as providing an important, a priori source of evidence for hypotheses about the contents of our implicit referential policies with regard to our terms. But all such hypotheses have a potential falsifier that is only discoverable empirically. In other words, gold-standard evidence for such hypotheses is always empirical.

There are two reasons, I claim, scientists do and should ignore standard philosophical theories of objective evidence: (1) Such theories propose concepts that are far too weak to give scientists what they want from evidence, viz., a good reason to believe a hypothesis; and (2) They provide concepts that make the evidential relationship a priori, whereas typically establishing an evidential claim requires empirical investigation.

This paper argues that a priori justification is, in principle, compatible with naturalism—if the a priori is understood in a way that is free of the inessential properties that, historically, have been associated with the concept. I argue that empirical indefeasibility is essential to the primary notion of the a priori; however, the indefeasibility requirement should be interpreted in such a way that we can be fallibilist about apriori-justified claims. This fallibilist notion of the a priori accords with the naturalist’s commitment to scientific methodology in that it allows for apriori-justified claims to be sensitive to further conceptual developments and the expansion of evidence. The fallibilist apriorist allows that an a priori claim is revisable in only a purely epistemic sense. This modal claim is weaker than what is required for a revisability thesis to establish empiricism, so fallibilist apriorism represents a distinct position.