The aim of this dissertation is to explore Wilfrid Sellars’s philosophy of language and, in particular, his theory of the linguistic meaning. Sellars is famous for having outlined a way to systematically understand the meaning of linguistic expressions in terms of their use. According to Sellars, the meaning of linguistic expressions is determined in the space of reasons. This means that the meaning of a linguistic expression is determined by the role it plays in our inferential practice, the practice of giving and asking for reasons. This idea is nowadays called ‘inferential role semantics’ or ‘inferentialism’ and its possibility and prospects are under close scrutiny. This dissertation examines Sellars’s inferentialist account of the linguistic meaning with a special focus on issues that are directly or indirectly related to conceptual change or conceptual revision. Although conceptual change or conceptual revision was one of his central concerns, Sellars never developed its systematic account. This dissertation aims to reconstruct Sellars’s account of inference, meaning, and conceptual change by closely reading his 1968 book Science and Metaphysics and his 1973 paper “Conceptual Change,” in both of which he discusses conceptual change in detail, gathering his scattered remarks on conceptual change, situating his views in the historical context, and showing the relevance his views have to contemporary debates.

              Although this dissertation primarily aims to contribute to understanding Sellars’s account of inference, meaning, and conceptual change, besides the Sellars scholarship, there are three areas of philosophical studies to which this dissertation also aims to contribute: (1) a study of inferentialism in the philosophy of language; (2) normative studies of concepts and their foundational studies in metaphilosophy, which are called ‘conceptual engineering’ or ‘conceptual ethics’; and (3) a study of the history of post-war analytic philosophy. This dissertation aims to contribute to these areas in the following way:

 

(1) A study of inferentialism in the philosophy of language:

              Sellars’s idea of explaining the meaning of linguistic expressions in terms of the role they play in our inferential practice is now familiar due to Robert Brandom’s systematic effort to develop it under the label ‘inferentialism.’ Brandom inherited some of Sellars’s basic ideas, working them out in much more detail than Sellars did. But Brandom also diverges from Sellars in some respects. One of the aims of this dissertation is to identify where Brandom diverges from Sellars, and explore the possibility of a more Sellarsian form of inferentialism, which is different from Brandom’s more standard one in some respects. As I discuss in Chapter 3, while Sellars accepts a form of the analytic-synthetic distinction, Brandom does not. Chapter 3 thus explores the possibility of a form of inferentialism that accepts the analytic-synthetic distinction. And as I discuss in Chapter 4, while Sellars appeals to the Peircean ideal perspective, Brandom does not. Chapter 4 considers how the ideal perspective might work as the regulative ideal in our inquiry.

              This dissertation also aims to contribute to a study of inferentialism by responding to an objection to it. Inferentialism is sometimes said to be a static framework. In particular, it is sometimes objected that it cannot provide a way to distinguish conceptual revision from conceptual replacement. I respond to this objection by reconstructing Sellars’s account of conceptual revision in Chapter 1. This will serve as a defense of inferentialism.

 

(2) Normative studies of concepts and their foundational studies:

              In recent years, there is a growing interest in what is called ‘conceptual engineering’ or ‘conceptual ethics.’ Both conceptual engineering and conceptual ethics are normative studies of concepts, which aim to reflectively examine, evaluate, and improve our conceptual repertoire. They are concerned with normative questions such as “Should we use the concept of X?” or “How should we use it?” As interest in normative studies of concepts grows, so does interest grow in their foundational questions such as “What is a good conceptual revision?” and “How is conceptual revision possible at all?” It is these foundational issues of normative studies of concepts that are the topic of the first two chapters of this dissertation. Chapter 1 provides a way to distinguish conceptual revision from conceptual replacement by reconstructing Sellars’s account of conceptual revision. Chapter 2 reconstructs Sellars’s pragmatist account of justification of concepts These discussions show the relevance of Sellars’s account of inference, meaning, and conceptual change to contemporary discussions.

 

(3) A study of the history of analytic philosophy:

              In recent years, there is also a growing interest in the history of analytic philosophy. Now, not only Frege, Russell, and Wittgenstein, but also Carnap and Quine have become subjects of extensive historical studies. Sellars has also begun to be studied historically. However, what position Sellars occupied in relation to other leading figures of post-war analytic philosophy is still unclear.

              However, Sellars himself engaged in dialogues with such philosophers as Carnap, Quine, and Putnam. As I discuss in Chapter 3, Sellars defended a form of the analytic-synthetic distinction against Quine’s attack from an inferentialist perspective. And as I discuss in Chapter 4, there was a neglected debate between Sellars and Putnam on semantic externalism in 1973. Further, Chapter 2 notes that Sellars, Carnap, and Feigl held similar views on justification of concepts. The discussions in these chapters will stimulate further dialogues among historians of analytic philosophy. Further, situating Sellars in the historical context will also help better understand his philosophy.

 

              In short, this dissertation aims to reconstruct Sellars’s account of inference, meaning, and conceptual change and thereby to contribute not only to a better understanding of Sellars’s philosophy but also to a study of inferentialism, foundational studies of normative studies of concepts, and a study of the history of analytic philosophy.

              This dissertation is structured as follows. Chapter 1 examines what contribution Sellars can make to a contemporary discussion on the problem of the limits of conceptual revision. The problem is to provide a way to distinguish conceptual revision from conceptual replacement. Although it is sometimes thought that inferentialists have difficulty addressing this problem, I argue that Sellars suggests an inferentialist way to deal with this problem. The key is a distinction between the identity of a concept itself and the sameness of the subject which a concept is a concept of. According to Sellars, conceptual revision only requires the sameness of the subject. While the identity of a concept requires the identity of the inferential role, the sameness of the subject only requires the similarity of the inferential role. Thus, even if inferentialists individuate concepts very finely, they can still make room for conceptual revision as distinguished from conceptual replacement.

              Chapter 2 reconstructs Sellars’s pragmatist account of justification of concepts. Following Sellars, I first trace the problem of justification of concepts to Hume and Kant, and then note that similar problems are widely discussed in various areas of contemporary philosophy. According to Sellars, there is no fixed basic set of concepts to which we could not seek alternatives. Evaluation and justification of concepts can only be carried out within an ongoing inquiry. Further, he thinks that it is not a concept itself but its adoption that is to be justified, and it is to be justified pragmatically by using practical reasoning.

              Chapter 3 examines Sellars’s account of analyticity or truths in virtue of meaning. The analytic-synthetic distinction was held by Carnap and other logical positivists, and famously attacked by Quine as a dogma of empiricism in his “Two Dogmas of Empiricism” (1951). However, even after Quine published his “Two Dogmas,” Sellars still maintained a form of the analytic-synthetic distinction or truths in virtue of meaning. The questions I aim to answer there are “How does Sellars respond to Quine’s attack?” and “How are Sellars’s and Carnap’s responses to Quine different?” I argue that although both Sellars and Carnap defend analyticity by explaining it in terms of the linguistic rules, they explain linguistic rules differently.

              Chapter 4 examines a neglected debate between Sellars and Putnam on semantic externalism in 1973. In his 1975 paper “The Meaning of ‘Meaning,’” Putnam famously argued for what is nowadays called ‘semantic externalism.’ However, already in 1973, Sellars and Putnam discussed the idea of the linguistic division of labor and the Twin Earth thought experiment. By reconstructing how Sellars replied to Putnam’s externalism, I argue that Sellars not only accepts the idea of the linguistic division of labor but also suggests how inferentialists can accommodate the Twin Earth thought experiment. Sellars’s key idea is that substance terms have a “promissory note aspect” which is to be cashed out in a successor conceptual framework. I reconstruct Sellars’s position as ideal successor externalism, and compare it with temporal externalism.

              In conclusion, I argue that Sellars’s account of inference, meaning, and conceptual change, which he developed by engaging in dialogues with his contemporaries, has the potential to contribute to new discussions on inferentialism and foundational studies of normative studies of concepts.