In his third and concluding volume, Lloyd P. Gerson presents an innovative account of Platonism, the central tradition in the history of philosophy, in conjunction with Naturalism, the "anti-Platonism" in antiquity and contemporary philosophy. Gerson contends that Platonism identifies philosophy with a distinct subject matter, namely, the intelligible world and seeks to show that the Naturalist rejection of Platonism entails the elimination of a distinct subject matter for philosophy. Thus, the possibility of philosophy depends on the truth of Platonism. From Aristotle to Plotinus to Proclus, Gerson clearly links the construction of the Platonic system well beyond simply Plato's dialogues, providing strong evidence of the vast impact of Platonism on philosophy throughout history. Platonism and Naturalism concludes that attempts to seek a rapprochement between Platonism and Naturalism are unstable and likely indefensible.

This study addresses a central theme in current philosophy: Platonism vs Naturalism and provides accounts of both approaches to mathematics, crucially discussing Quine, Maddy, Kitcher, Lakoff, Colyvan, and many others. Beginning with accounts of both approaches, Brown defends Platonism by arguing that only a Platonistic approach can account for concept acquisition in a number of special cases in the sciences. He also argues for a particular view of applied mathematics, a view that supports Platonism against Naturalist alternatives. Not only does this engaging book present the Platonist-Naturalist debate over mathematics in a comprehensive fashion, but it also sheds considerable light on non-mathematical aspects of a dispute that is central to contemporary philosophy.

Was Plato a Platonist? While ancient disciples of Plato would have answered this question in the affirmative, modern scholars have generally denied that Plato’s own philosophy was in substantial agreement with that of the Platonists of succeeding centuries. In From Plato to Platonism, Lloyd P. Gerson argues that the ancients were correct in their assessment. He arrives at this conclusion in an especially ingenious manner, challenging fundamental assumptions about how Plato’s teachings have come to be understood. Through deft readings of the philosophical principles found in Plato's dialogues and in the Platonic tradition beginning with Aristotle, he shows that Platonism, broadly conceived, is the polar opposite of naturalism and that the history of philosophy from Plato until the seventeenth century was the history of various efforts to find the most consistent and complete version of "anti-naturalism."Gerson contends that the philosophical position of Plato—Plato’s own Platonism, so to speak—was produced out of a matrix he calls "Ur-Platonism." According to Gerson, Ur-Platonism is the conjunction of five "antis" that in total arrive at anti-naturalism: anti-nominalism, anti-mechanism, anti-materialism, anti-relativism, and anti-skepticism. Plato’s Platonism is an attempt to construct the most consistent and defensible positive system uniting the five "antis." It is also the system that all later Platonists throughout Antiquity attributed to Plato when countering attacks from critics including Peripatetics, Stoics, and Sceptics. In conclusion, Gerson shows that Late Antique philosophers such as Proclus were right in regarding Plotinus as "the great exegete of the Platonic revelation."

What are the objects of science? Are they just the things in our scientific experiments that are located in space and time? Or does science also require that there be additional things that are not located in space and time? Using clear examples, these are just some of the questions that Scott Berman explores as he shows why alternative theories such as Nominalism, Contemporary Aristotelianism, Constructivism, and Classical Aristotelianism, fall short. He demonstrates why the objects of scientific knowledge need to be not located in space or time if they are to do the explanatory work scientists need them to do. The result is a contemporary version of Platonism that provides us with the best way to explain what the objects of scientific understanding are, and how those non-spatiotemporal things relate to the spatiotemporal things of scientific experiments, as well as everything around us, including even ourselves.

"Aristotle versus Plato. For a long time that is the angle from which the tale has been told, in textbooks on the history of philosophy and to university students. Aristotle's philosophy, so the story goes, was au fond in opposition to Plato's. But it was not always thus."—from the Introduction In a wide-ranging book likely to cause controversy, Lloyd P. Gerson sets out the case for the "harmony" of Platonism and Aristotelianism, the standard view in late antiquity. He aims to show that the twentieth-century view that Aristotle started out as a Platonist and ended up as an anti-Platonist is seriously flawed. Gerson examines the Neoplatonic commentators on Aristotle based on their principle of harmony. In considering ancient studies of Aristotle's Categories, Physics, De Anima, Metaphysics, and Nicomachean Ethics, the author shows how the principle of harmony allows us to understand numerous texts that otherwise appear intractable. Gerson also explains how these "esoteric" treatises can be seen not to conflict with the early "exoteric" and admittedly Platonic dialogues of Aristotle. Aristotle and Other Platonists concludes with an assessment of some of the philosophical results of acknowledging harmony.

Platonism has played a central role in Christianity and is essential to a deep understanding of the Christian theological tradition. At times, Platonism has constituted an essential philosophical and theological resource, furnishing Christianity with an intellectual framework that has played a key role in its early development, and in subsequent periods of renewal. Alternatively, it has been considered a compromising influence, conflicting with the faith's revelatory foundations and distorting its inherent message. In both cases the fundamental importance of Platonism, as a force which Christianity defined itself by and against, is clear. Written by an international team of scholars, this landmark volume examines the history of Christian Platonism from antiquity to the present day, covers key concepts, and engages issues such as the environment, natural science and materialism.

Many contemporary Anglo-American philosophers describe themselves as naturalists. But what do they mean by that term? Popular naturalist slogans like, "there is no first philosophy" or "philosophy is continuous with the natural sciences" are far from illuminating. "Understanding Naturalism" provides a clear and readable survey of the main strands in recent naturalist thought. The origin and development of naturalist ideas in epistemology, metaphysics and semantics is explained through the works of Quine, Goldman, Kuhn, Chalmers, Papineau, Millikan and others. The most common objections to the naturalist project - that it involves a change of subject and fails to engage with "real" philosophical problems, that it is self-refuting, and that naturalism cannot deal with normative notions like truth, justification and meaning - are all discussed. "Understanding Naturalism" distinguishes two strands of naturalist thinking - the constructive and the deflationary - and explains how this distinction can invigorate naturalism and the future of philosophical research.