Mi-Kyoung Lee

The Theaetetus is a principal field of battle for one of the main disputes between Plato's interpreters. This is the dispute between unitarians and revisionists. This article focuses on Plato's ideas on unitarians and revisionists. Plato's greatest work on epistemology, in the Theaetetus, Plato has much to say about the nature of knowledge elsewhere. But only the Theaetetus offers a set-piece discussion of the question “What is knowledge?” This question is raised most vividly for readers of Plato when assessing the central epistemological claim of the Republic: that knowledge is impossible unless one grasps the forms, and also for those who do not recognize the existence of the forms. Plato adopts a complex strategy for examining the nature of knowledge in the Theaetetus: he sometimes has Socrates examine a conception of knowledge purely on its own terms. The two major ideas dealt with in the article are change and form.

Farnesyltransferase inhibitors are anticancer compounds that inhibit Ras GTPases. Since Ras GTPases play key roles in T cell activation and function, we hypothesized that FTIs have immunomodulatory properties and are potential antirejection agents. An investigation was performed on a potent FTI to evaluate this hypothesis in the in vitro setting. The in vitro effects of the FTI A-228839 were evaluated. Lectin- or antigen presenting cell -induced lymphocyte proliferation in the presence of A-228839 was measured. The effects of A-228839 on 1E5 T cell polarity were assessed by microscopy. Intracellular calcium kinetics of lectin-activated lymphocytes was monitored by flow cytometry. The effects of A-228839 on peripheral blood mononuclear cell cytokine production was assessed by a cytometric bead array method. Activation-induced apoptosis was measured with an annexin V staining assay. A-228839 inhibited lectin-induced proliferation. The inhibitory effects of A-228839 on lectin induced lymphocyte proliferation were additive to those of CsA. A-228839 was more effective in inhibiting APC-induced T cell proliferation. A-228839 significantly disrupted the polarized shape of 1E5 T cells at physiologic concentrations. A-228839 altered PBMC baseline [Ca2+]i but did not affect [Ca2+]i kinetics during lectin-induced lymphocyte activation. A-228839 inhibited lymphocyte Th1 cytokine production at submicromolar levels and promoted apoptosis in lectin-activated lymphocytes. A-228839 potently inhibits lymphocyte activation and function. Our results suggest that FTIs may represent a new class of clinically useful immunomodulatory agents. A-228839 has potent in vitro immunomodulatory properties that warrant in vivo evaluation as an antirejection agent. © 2002 Elsevier Science B.V. All rights reserved.

In this thesis, I present an account of the development of early Greek epistemology, according to which Protagoras' measure doctrine, and his argument from conflicting appearances, was the starting point for work on perception and knowledge by Plato in the Theaetetus, Aristotle in Metaphysics IV and Democritus. In Chapter One, I argue against the assumption that Protagoras' Aletheia contained a philosophical theory. It was probably not a treatise, but a virtuoso show-piece, with the aim of "knocking down" views according to which truth is only known by gods, and, with difficulty, by privileged humans--namely, philosophers. For this, it need not have contained more than some well-chosen examples of perceptual and value beliefs, and arguments that one cannot decide which are true. In Chapter Two, I argue that Democritus should be seen as Protagoras' heir. Democritus argued Protagoras' general claim is self-refuting, but thought he was right about perceptual appearances. In Confirmations, he defended the senses, attributing to them knowledge and "power of proof." However, his theory led to an ancestor of the primary/secondary quality distinction, and this threatened to undermine the theory itself because of implications--that one can only know how things appear and not how things are by nature--which were later taken up in Pyrrhonist skepticism. In Chapter Three, I present a reading of the Secret Doctrine in Plato's Theaetetus as a defense and diagnosis of Protagoras' claim, in particular, an explanation of the global relativization which Protagoras' claim seems to recommend. This reading is meant to avoid the well-known difficulties concerning the prevailing interpretation of Protagoras' "Secret Doctrine" as a flux doctrine. I also argue that Plato developed the Secret Doctrine with Democritus in mind. In Chapter Four, I argue that Plato's "self-refutation argument" is aimed at relativism, but not relativism about truth. The latter, which Aristotle dismisses as eristical, is a position Protagoras can take, but Plato's argument works against it as well. In Chapter Five, I examine why Aristotle seems to treat Protagoras in Metaphysics IV as being committed to a denial of the principle of non-contradiction.

Relativism, the position that things are for each as they seem to each, was first formulated in Western philosophy by Protagoras, the 5th century BC Greek orator and teacher. This book focuses on the challenge to the possibility of expert knowledge posed by Protagoras, together with responses by the three most important philosophers of the next generation, Plato, Aristotle, and Democritus. In his book Truth, Protagoras made vivid use of two provocative but imperfectly spelled out ideas. First, that everyone is a ‘measure’ of the truth, and that everyone is already capable of determining how things are, since the senses are the best and most credible guides to the truth. Second, given that things appear differently to different people, there is no basis on which to decide that one appearance is true rather than the other. Plato developed these ideas into a more fully worked-out theory, which he then subjected to refutation in the Theaetetus. Aristotle argued that Protagoras’ ideas lead to skepticism in Metaphysics Book G, a chapter which reflects awareness of Plato’s reaction in the Theaetetus. Finally, Democritus incorporated modified Protagorean ideas and arguments into his theory of knowledge and perception. There have been many important recent studies of these thinkers in isolation. However, there has been no attempt to tell a single, coherent story about how Democritus, Plato, and Aristotle responded to Protagoras’ striking claim, and to its perceived implications about knowledge, perception, and truth. This book offers a new account of this important chapter in the development of Greek epistemology.