This chapter draws some broad contrasts between the theory of singular compositional abduction and various Peircean accounts of abduction. In brief, Peirce and the Neo-Peirceans believe that scientists use abduction to introduce hypotheses, whereas I maintain that scientists sometimes use singular compositional abduction to confirm hypotheses. Peirce and the Neo-Peirceans have proposed that scientists hypothetico-deductively confirm hypotheses. Further, neither Peirce nor the Neo-Peirceans develop a theory of compositional explanation suitable for the case studies reviewed in Chapters 5 and 6. Moreover, their project is not focused on providing an account of scientific experimental work.

This brief concluding chapter provides a broad brush summary of the book. If historians and philosophers of science are interested in how scientists confirm compositional hypotheses, then an important resource is the scientific literature wherein scientists appeal to experimental results. This is where the theory of singular compositional abduction provides a novel account. The book ends on a note about the incompleteness of the theory. For one thing, the theory does not provide an account of how functional magnetic resonance imaging might be used to confirm compositional hypotheses.

This chapter proposes that singular compositional abduction has four features shared by at least many other instances of abduction: (1) abduction is sometimes used for confirmation, (2) abduction is sometimes used to postulate entities that are qualitatively distinct from the entities cited in the supporting evidence, (3) abduction may rely on background beliefs, and (4) abduction is sometimes used to postulate entities that are not directly empirically detected. It also indicates why scientists take abduction to be truth conducive. It shows how compositional abduction may serve as an alternative to the theory of hypothetico-deductive confirmation. Finally, it suggests a broad range of scientific cases in cognitive science that might be understood in terms of singular compositional abduction.