Putnam’s insight was this: Some statements which were considered analytic or a priori (where a priori is understood to mean immune to revision) turned out to be false. Those who held such statements immune to revision were unable to see how the statement could be false until a new theory allowed them to. Putnam’s paradigm example is that of the shift from a Euclidean to a non-Euclidean conception of physical space. A geometer or physicist living in the time of Hume might have said it is true by definition that the sum of the angles of a triangle in physical space cannot not exceed 180°. This follows from the supposition (if we can call it a supposition for those who had no alternative view) that space is Euclidean. As it turns out, space is not Euclidean, and so the sum of the angles of a triangle in physical space can exceed 180°. But this suggestion could not have been made sense of until non-Euclidean geometry had been developed. 

The statement that physical space is Euclidean, then, being false, can be neither analytic nor a priori. How are we to explain its status as apparently immune to revision before the development of non-Euclidean geometry? Putnam proposes that we consider such statements to be contextually a priori—immune to revision unless a new theory or conceptual scheme permits us to specify some way in which it might be false. As stated, it is with this notion of contextual apriority which my thesis is concerned. The thesis is split into two broad parts. The first is a survey of Putnam’s writings relating to contextual apriority. These writings span his entire career, and I divide them into three periods of development. In Putnam’s first period, covering his published works between 1962 and 1978, he defends the thesis that no statement is immune to revision, and all alleged absolutely a priori (i.e., absolutely unrevisable) statements are, in fact, contextually a priori. In his second period, constituted by a single paper published in 1978, Putnam decides that there must be at least one truth which is absolutely immune to revision. After this period and for the remainder of his career, he held to the view that, while we cannot say of any given contextually a priori statement that it is either revisable or immune to revision, we can functionally hold such statements immune to revision while remaining methodologically open to the possibility of a new conceptual scheme enabling us to see a way in which the statements might be false. 

The position held by Putnam in what I call his third period serves as the starting point for the second part of my thesis. The goal of this part is to clarify some difficult issues relating to Putnam’s notion and to defend it against objections. In the first section, I consider what it means for Putnam’s notion to be one of methodological (or epistemological) significance, and what it means for us to be entitled to accept contextually a priori statements. I also introduce a serious objection raised by Gary Ebbs to Putnam’s notion, and introduce and dismiss an objection to the effect that contextual apriority is a deficient notion if it can be used to justify acceptance of absolutely a priori statements. In the second section of this second part of the thesis, I consider at length the way Putnam thinks about conceivability, which is significant given that contextual apriority is usefully framed in terms of conceivability—a statement is contextually a priori, says Putnam, when its negation is inconceivable. I present David Chalmers’ framework for thinking about conceivability as a kind of foil to Putnam’s view. I explain in detail why Putnam must reject much of the way Chalmers talks of conceivability. Chalmers’ thinking on conceivability is inextricably bound up with his two-dimensional semantics. So-called primary conceivability (which, for Chalmers, is a way of thinking about a state of affairs which requires us to use semantically neutral terms to construct a possible world which we can consider as actual) is superficially similar to the kind of conceivability in which Putnam is interested, but ultimately is a notion Putnam cannot accept given his semantic commitments. Primary conceivability (as Chalmers presents it) entails that there are unrevisable analytic truths, which is what Putnam argues against. I close the section by considering the suggestion, also of great import in Chalmers’ work, that there are unrevisable material conditionals immune to Quine’s criticisms. The final section in the paper establishes the kind of conceivability necessary for contextually a priori entitlement. It also suggests that Putnam implicitly considered there to be a systematic import requirement for contextual apriority, which in turn suggests that the notion of absolute apriority is not itself a notion of real methodological significance. Finally, I attempt to work out how contextual apriority might be defended against the difficult objections made by Gary Ebbs, which were raised earlier in the paper.

Needless to say, if Putnam was right about the status of statements traditionally held to be immune to revision, there are far-reaching implications. His work in this area touches on epistemology, the history and philosophy of science, modality, and the philosophy of language. It has implications for many further areas of philosophy. This is evident in my thesis from the way in which Putnam’s work can be put to use in resisting the kind of conceptual analysis and two-dimensional semantics endorsed by Chalmers, in addition to the wide-ranging topics which receive attention in the course of considering Putnam’s important contributions—externalist and two-dimensional semantics, the nature of conceivability, the relationship between conceivability and possibility, analyticity, apriority, and more. 

Joseph joined the Yale University Philosophy Ph.D. program in 2022 after completing undergraduate degrees in Philosophy (Honors) and Classical Studies at Indiana University. His primary interests lie at the intersection of philosophy of language, epistemology, and metaphysics. He is particularly interested in Hilary Putnam’s work on reference, apriority, and related topics. Joseph has secondary interests in Early Modern philosophy and philosophy of religion. He is married and has two children.

David Chalmers, writing in “Three Puzzles About Spatial Experience,” calls extrinsicalism the “consensus” position, while David Baker, writing in “‘The Experience of Left and Right’ Meets the Physics of Left and Right,” says “I speak for a large population of specialists in asserting that [extrinsicalism] is far more plausible than [intrinsicalism].” In his honors thesis, however, Eli synthesized research from physical biochemistry and the Standard Model of particle physics to argue in favor of the contrary intrinsicalist thesis: that incongruent counterparts differ with regard to some non-relational intrinsic property. 

In organic chemistry, a compound is said to be chiral when it contains one or more chiral centers, carbon atoms that are bonded to four or more different chemical groups. Take, for example, the compound R-2-butanol:

To the chemist, chiral compounds are notable for the fact that they are always members of incongruent pairs; together, these non-superimposable, mirrored molecules are called enantiomers. The “R” in R-2-Butanol, in fact, denotes a specific enantiomer of 2-Butanol, with its corresponding mirror image denoted with an “S.”

For much of chemical history, enantiomers were believed to differ only in relation to one another. In the mid-1950s, however, the work of physicist Chien-Shiung Wu began to call this orthodoxy into question: through a ground-breaking series of experiments, Wu and her colleagues demonstrated that electroweak forces treat incongruent counterparts differently. Soon after the publication of Wu’s results, theoretical biologists began to predict that these electroweak forces would cause enantiomers—such as R-2- and S-2-butanol—to differ, particularly in the metric of Gibbs Free Energy (G). G is a thermodynamic quantity, describing the amount of reversible work that may be done by a given isobaric and isothermal system; in the context of biochemistry, G can roughly be thought of as the amount of energy stored in a molecule’s bonds. Over the fifty years since this initial proposal, an increasingly complex series of studies has attempted to quantify the difference in Gibbs Free Energy between enantiomers (referred to as ΔG), with specific focus on the differences between carbohydrate and amino acid enantiomers. These studies first approached the question of quantifying ΔG from a theoretical perspective, employing ab initio calculations that take only physical constants as inputs and make no assumptions about a compound’s environment. By these calculations, ΔG is incredibly small—10^-12 J/mol to 10^-15 J/mol—but a ΔG due to electroweak forces is nonetheless universally regarded as extant. While the direction of the inequality is a matter of scientific debate, the existence of a difference, under any set of conditions, is not.

If the phenomenon of ΔG is to constitute an objection to the extrinsicalist thesis, however, G must be an intrinsic property that can be defined without reference to an external object. At a fundamental level, this can be accomplished through two different forms of argument. First, we can argue for this claim from an empirical standpoint. For a given compound under any set of constant conditions, G itself is a constant and characteristic quantity. Since G is essentially a measure of the energy contained in the bonds of a compound, any two compounds with the same G will have the same bonds in the same orientations. If G is defined in terms of a compound’s bonds, no object external to the compound is required to define G, and G, therefore, is an intrinsic property. However, we can also look at this question from a more intuitive perspective and echo back to a classic example considered by Kant: if the universe contained only one enantiomer of a molecule, could we determine whether it was the R- or S-enantiomer? The answer arising from research on ΔG leads us to answer affirmatively. ΔG entails a difference between the G of enantiomers, and as such, a precise enough analysis of our lone enantiomer’s energy could be used to determine its R- or S-enantiomerism. Again, we are guided to the conclusion that G is intrinsic, as no other object in the universe is needed to define G, or further, to distinguish one enantiomer from the other. By considering both of these arguments, we have grounds to believe that G is in fact intrinsic, and insofar as research on ΔG entails a difference in G between enantiomers, we have also motivated the intrinsicalist thesis. 

Though this finding directly relates to the philosophy of physics, the conclusion Eli developed has implications in phenomenology and epistemology. In the context of phenomenology, the extrinsicalist thesis has been applied by numerous authors to advance or analyze surprising conclusions about the structure of left/right experiences. In “A puzzle about the experience of left and right,” for example, Brian Cutter develops a paradox between the phenomenology and metaphysics of orientation through reference to extrinsicalism, arguing for a disjunctive conclusion: either there is a degree of independence between phenomenology and what our experience represents, or spatial properties presented in perception are mind-dependent or illusory. But if extrinsicalism is abandoned in favor of the intrinsicalist thesis, this paradox vanishes. In the context of epistemology, David Chalmers, writing in “Three Puzzles About Spatial Experience,” seeks to motivate the impossibility of lifelong illusions about orientation through an appeal to the extrinsicalist thesis; but if the extrinsicalist thesis fails, Chalmers cannot reach his conclusion. These considerations, when taken together, have significant impacts in the philosophy of physics, in how we understand perception, and in epistemology, supporting skeptical hypotheses in each of these fields.

After completing his undergraduate degree in Philosophy at Indiana University, Eli G. Schantz is currently a medical student at Indiana University School of Medicine—South Bend, where his research centers on ontology and its application to debates in bioethics and the philosophy of medicine. He also serves as a delegate to the Indiana State Medical Association and the Medical Student Section of the American Medical Association, where he sits on the AMA-MSS Committee on Bioethics and Humanities and advocates for ethics-informed healthcare policy.