Joseph LaPorte offers a new account of the connections between the reference of words for properties and kinds, and theoretical identity statements. Some terms for concrete objects, such as 'Hesperus' and 'Phosphorus', are rigid, and the rigidity of these terms is important because it helps to determine whether certain statements containing them, including identity statements like 'Hesperus = Phosphorus', are necessary or contingent. These observations command broad agreement. But there has been much less agreement about whether and how designators for properties are rigid: terms like 'white', 'brontosaur', 'beautiful', 'heat', 'H2O', 'pain', and so on. In Rigid Designation and Theoretical Identities, LaPorte articulates and defends the position that terms for properties are rigid designators. Furthermore, he argues that property designators' rigidity is put to good use in important philosophical arguments supporting and impugning certain theoretical identity statements. The book as a whole constitutes a broad defense of a tradition originating largely in seminal work from Saul Kripke, which affirms the truth and necessity of theoretical identities such as 'water = H2O', 'heat = the motion of molecules' and the like, and which looks skeptically upon psychophysical identities like 'pain = c-fiber firing'. LaPorte responds to detractors of the Kripkean tradition whose objections and challenges indicate where development and clarification is needed, as well as to sympathizers who have put forward important contributions toward such ends. Specific topics discussed by way of defending the Kripkean tradition include conventionalism and empiricism, nominalism about properties, multiple realizability, supervenience, analytic functionalism, conceptual dualism and 'new wave' or a posteriori materialism, the explanatory gap, scientific essentialism (more broadly: scientific necessitarianism), and vitalism.

According to the received tradition, the language used to to refer to natural kinds in scientific discourse remains stable even as theories about these kinds are refined. In this illuminating book, Joseph LaPorte argues that scientists do not discover that sentences about natural kinds, like 'Whales are mammals, not fish', are true rather than false. Instead, scientists find that these sentences were vague in the language of earlier speakers and they refine the meanings of the relevant natural-kind terms to make the sentences true. Hence, scientists change the meaning of these terms, This conclusions prompts LaPorte to examine the consequences of this change in meaning for the issue of incommensurability and for the progress of science. This book will appeal to students and professional in the philosophy of science, the philosophy of biology and the philosophy of language.

Joseph LaPorte argues that scientists have not discovered that sentences about natural kinds are true rather than false. Instead, scientists have found that these sentences were vaguely phrased in the language of earlier speakers and they have thus refined the meanings of the terms to validate the sentences. In the process, however, they have also changed the meaning of the terms. This book will appeal to students and professionals in the philosophy of science, the philosophy of biology and the philosophy of language.