This is the 2011 Aquinas Lecture delivered by John McDowell on February 27, 2011 at Marquette University. A central theme in much of Professor McDowell's work is the harmful effect, in modern philosophy and in the modern reception of pre-modern philosophy, of a conception of nature that reflects an understanding, in itself perfectly correct, of the proper goals of the natural sciences. He has argued that we can free ourselves from the characteristic sorts of philosophical anxiety by recalling the possibility of a less restrictive conception of what it takes for something to be natural.

Tyler Burge's study investigates the most primitive ways in which individuals represent the physical world. By reflecting on the science of perception and related psychological and biological sciences, Burge outlines the constitutive conditions for perceiving the physical world, thus locating the origins of representational mind.

Duncan Pritchard offers an account of perceptual knowledge, arguing that it is paradigmatically constituted by true belief that enjoys rational support which is reflectively accessible to the agent. This resolves the issue between intermalism and externalism, and poses a radical challenge to contemporary epistemology.

How does perceptual experience make us knowledgeable about the world? In this book Nadja El Kassar argues that an informed answer requires a novel theory of perception: perceptual experience involves conceptual capacities and consists in a relation between a perceiver and the world. Contemporary theories of perception disagree about the role of content and conceptual capacities in perceptual experience. In her analysis El Kassar scrutinizes the arguments of conceptualist and relationist theories, thereby exposing their limitations for explaining the epistemic role of perceptual experience. Against this background she develops her novel theory of epistemically significant perception. Her theory improves on current accounts by encompassing both the epistemic role of perceptual experiences and its perceptual character. Central claims of her theory receive additional support from work in vision science, making this book an original contribution to the philosophy of perception.

How does perception provide reasons for our empirical judgements? This volume offers a set of new essays which in different ways address this fundamental question, and investigate the implications for our understanding of perceptual experience.

Do we have introspective access to our own thoughts? Peter Carruthers challenges the consensus that we do: he argues that access to our own thoughts is always interpretive, grounded in perceptual awareness and sensory imagery. He proposes a bold new theory of self-knowledge, with radical implications for understanding of consciousness and agency.

Anthony J. Lisska presents a new analysis of Thomas Aquinas's theory of perception. While much work has been undertaken on Aquinas's texts, little has been devoted principally to his theory of perception and less still on a discussion of inner sense. The thesis of intentionality serves as the philosophical backdrop of this analysis while incorporating insights from Brentano and from recent scholarship. The principal thrust is on the importance of inner sense, a much-overlooked area of Aquinas's philosophy of mind, with special reference to the vis cogitativa. Approaching the texts of Aquinas from contemporary analytic philosophy, Lisska suggests a modest 'innate' or 'structured' interpretation for the role of this inner sense faculty. Dorothea Frede suggests that this faculty is an 'embarrassment' for Aquinas; to the contrary, the analysis offered in this book argues that were it not for the vis cogitativa, Aquinas's philosophy of mind would be an embarrassment. By means of this faculty of inner sense, Aquinas offers an account of a direct awareness of individuals of natural kinds—referred to by Aquinas as incidental objects of sense—which comprise the principal ontological categories in Aquinas's metaphysics. By using this awareness of individuals of a natural kind, Aquinas can make better sense out of the process of abstraction using the active intellect (intellectus agens). Were it not for the vis cogitativa, Aquinas would be unable to account for an awareness of the principal ontological category in his metaphysics.

What do we see? We are visually conscious of colors and shapes, but are we also visually conscious of complex properties such as being John Malkovich? In this book, Susanna Siegel develops a framework for understanding the contents of visual experience, and argues that these contents involve all sorts of complex properties. Siegel starts by analyzing the notion of the contents of experience, and by arguing that theorists of all stripes should accept that experiences have contents. She then introduces a method for discovering the contents of experience: the method of phenomenal contrast. This method relies only minimally on introspection, and allows rigorous support for claims about experience. She then applies the method to make the case that we are conscious of many kinds of properties, of all sorts of causal properties, and of many other complex properties. She goes on to use the method to help analyze difficult questions about our consciousness of objects and their role in the contents of experience, and to reconceptualize the distinction between perception and sensation. Siegel's results are important for many areas of philosophy, including the philosophy of mind, epistemology, and the philosophy of science. They are also important for the psychology and cognitive neuroscience of vision.

In this book I present what seem to me (at the moment) to be right an swers to some of the main philosophical questions about the topics men tioned in the title, and I argue for them where I can. I hope that what I say may be of interest both to those who have already studied these ques tions a lot and to those who haven't. There are several important topics in epistemology to which I give little or no attention here - such as the nature of a proposition, the major classifications of propositions (neces sary and contingent, a priori and a posteriori, analytic and synthetic, general and particular), the nature of understanding a proposition, the nature of truth, the nature and justification of the various kinds of in ference (deductive, inductive, and probably others) -but enough is cover ed, to one degree or another, that the book might be of use in a course in epistemology. Earlier versions of some of the material in Chapters II, III, and IV were some of the material in Ginet (1970). An earlier version of the part of Chapter VII on memory-connection was a paper that I profited from reading and discussing in philosophy discussion groups at Cornell Uni versity, SUNY at Albany, and Syracuse University in 1972-73. I do not like to admit how long I have been working on this book.

According to the cognitive penetrability hypothesis, our beliefs, desires, and possibly our emotions literally affect how we see the world. This book elucidates the nature of the cognitive penetrability and impenetrability hypotheses, assesses their plausibility, and explores their philosophical consequences. It connects the topic's multiple strands (the psychological findings, computationalist background, epistemological consequences of cognitive architecture, and recent philosophical developments) at a time when the outcome of many philosophical debates depends on knowing whether and how cognitive states can influence perception. All sixteen chapters were written especially for the book. The first chapters provide methodological and conceptual clarification of the topic and give an account of the relations between penetrability, encapsulation, modularity, and cross-modal interactions in perception. Assessments of psychological and neuroscientific evidence for cognitive penetration are given by several chapters. Most of the contributions analyse the impact of cognitive penetrability and impenetrability on specific philosophical topics: high-level perceptual contents, the epistemological consequences of penetration, nonconceptual content, the phenomenology of late perception, metacognitive feelings, and action. The book includes a comprehensive introduction which explains the history of the debate, its key technical concepts (informational encapsulation, early and late vision, the perception-cognition distinction, hard-wired perceptual processing, perceptual learning, theory-ladenness), and the debate's relevance to current topics in the philosophy of mind and perception, epistemology, and philosophy of psychology.