Alvin (b.1932), one of the most important twentieth-century American philosophers of religion. His ideas have determined the direction of debate in many aspects of the discipline. He has also contributed substantially to analytic epistemology and the metaphysics of modality. Plantinga is currently director of the Center for Philosophy of Religion and John O’Brien Professor of Philosophy at the University of Notre Dame.
Plantinga’s philosophy of religion has centered on the epistemology of religious belief. His God and Other Minds (1967) introduced a defining claim of his career – that belief in God may be rational even if it is not supported by successful arguments from natural theology. This claim was fully developed in a series of articles published in the 1980s, in which he argued for the position he calls ‘Reformed Epistemology.’ Borrowing from the work of theologians such as Calvin, Bavinck, and Barth, Plantinga reasoned that theistic belief is ‘properly basic,’ justified not by other beliefs but by immediate experience. This position was most thoroughly treated in his article ‘Reason and Belief in God’ (Plantinga and Wolterstorff, eds., Faith and Rationality, 1983).
In early work Plantinga assumed an internalist view of epistemic justification. Later he moved to externalism, arguing that basic theistic belief would count as knowledge if true and appropriately produced. He developed this approach in ‘Justification and Theism’ (Faith and Philosophy, 1987). These ideas led to the development of a full-scale externalist epistemological theory, first presented in his 1989 Gifford Lectures and later published in the two-volume set Warrant: The Current Debate and Warrant and Proper Function (1993). This theory has become the focal point of much contemporary debate in analytic epistemology.
Plantinga is also a leading theorist in the metaphysics of modality. The Nature of Necessity (1974) developed a possible worlds semantics that has become standard in the literature. His analysis of possible worlds as maximally consistent states of affairs offers a realist compromise between nominalist and extreme reificationist conceptions. In the last two chapters, Plantinga brings his modal metaphysics to bear on two classical topics in the philosophy of religion. He presented what many consider the definitive version of the free will defense against the argument from evil and a modal version of the ontological argument that may have produced more response than any version since Anselm’s original offering.
See also EPISTEMOLOGY, EVIDENTIALISM , PHILOSOPHY OF RELIGION , POSSIBLE WORLD. J.F.S. Plato (427–347 B.C.), preeminent Greek philosopher whose chief contribution consists in his conception of the observable world as an imperfect image of a realm of unobservable and unchanging ‘Forms,’ and his conception of the best life as one centered on the love of these divine objects. Life and influences. Born in Athens to a politically powerful and aristocratic family, Plato came under the influence of Socrates during his youth and set aside his ambitions for a political career after Socrates was executed for impiety. His travels in southern Italy and Sicily brought him into closer contact with the followers of Pythagoras, whose research in mathematics played an important role in his intellectual development. He was also acquainted with Cratylus, a follower of Heraclitus, and was influenced by their doctrine that the world is in constant flux. He wrote in opposition to the relativism of Protagoras and the purely materialistic mode of explanation adopted by Democritus. At the urging of a devoted follower, Dion, he became involved in the politics of Syracuse, the wealthiest city of the Greek world, but his efforts to mold the ideas of its tyrant, Dionysius II, were unmitigated failures. These painful events are described in Plato’s Letters (Epistles), the longest and most important of which is the Seventh Letter, and although the authenticity of the Letters is a matter of controversy, there is little doubt that the author was well acquainted with Plato’s life. After returning from his first visit to Sicily in 387, Plato established the Academy, a fraternal association devoted to research and teaching, and named after the sacred site on the outskirts of Athens where it was located. As a center for political training, it rivaled the school of Isocrates, which concentrated entirely on rhetoric. The bestknown student of the Academy was Aristotle, who joined at the age of seventeen (when Plato was sixty) and remained for twenty years. Chronology of the works. Plato’s works, many of which take the form of dialogues between Socrates and several other speakers, were composed over a period of about fifty years, and this has led scholars to seek some pattern of philosophical development in them. Increasingly sophisticated stylometric tests have been devised to calculate the linguistic similarities among the dialogues. Ancient sources indicate that the Laws was Plato’s last work, and there is now consensus that many affinities exist between the style of this work and several others, which can therefore also be safely regarded as late works; these include the Sophist, Statesman, and Philebus (perhaps written in that order). Stylometric tests also support a rough division of Plato’s other works into early and middle periods. For example, the Apology, Charmides, Crito, Euthyphro, Hippias Minor, Ion, Laches, and Protagoras (listed alphabetically) are widely thought to be early; while the Phaedo, Symposium, Republic, and Phaedrus (perhaps written in that order) are agreed to belong to his middle period. But in some cases it is difficult or impossible to tell which of two works belonging to the same general period preceded the other; this is especially true of the early dialogues. The most controversial chronological question concerns the Timaeus: stylometric tests often place it with the later dialogues, though some scholars think that its philosophical doctrines are discarded in the later dialogues, and they therefore assign it to Plato’s middle period. The underlying issue is whether he abandoned some of the main doctrines of this middle period.
Early and middle dialogues. The early dialogues typically portray an encounter between Socrates and an interlocutor who complacently assumes that he understands a common evaluative concept like courage, piety, or beauty. For example, Euthyphro, in the dialogue that bears his name, denies that there is any impiety in prosecuting his father, but repeated questioning by Socrates shows that he cannot say what single thing all pious acts have in common by virtue of which they are rightly called pious. Socrates professes to have no answer to these ‘What is X?’ questions, and this fits well with the claim he makes in the Apology that his peculiarly human form of wisdom consists in realizing how little he knows. In these early dialogues, Socrates seeks but fails to find a philosophically defensible theory that would ground our use of normative terms.
The Meno is similar to these early dialogues – it asks what virtue is, and fails to find an answer – but it goes beyond them and marks a transition in Plato’s thinking. It raises for the first time a question about methodology: if one does not have knowledge, how is it possible to acquire it simply by raising the questions Socrates poses in the early dialogues? To show that it is possible, Plato demonstrates that even a slave ignorant of geometry can begin to learn the subject through questioning. The dialogue then proposes an explanation of our ability to learn in this way: the soul acquired knowledge before it entered the body, and when we learn we are really recollecting what we once knew and forgot. This bold speculation about the soul and our ability to learn contrasts with the noncommittal position Socrates takes in the Apology, where he is undecided whether the dead lose all consciousness or continue their activities in Hades. The confidence in immortality evident in the Meno is bolstered by arguments given in the Phaedo, Republic, and Phaedrus. In these dialogues, Plato uses metaphysical considerations about the nature of the soul and its ability to learn to support a conception of what the good human life is. Whereas the Socrates of the early dialogues focuses almost exclusively on ethical questions and is pessimistic about the extent to which we can answer them, Plato, beginning with the Meno and continuing throughout the rest of his career, confidently asserts that we can answer Socratic questions if we pursue ethical and metaphysical inquiries together. The Forms. The Phaedo is the first dialogue in which Plato decisively posits the existence of the abstract objects that he often called ‘Forms’ or ‘Ideas.’ (The latter term should be used with caution, since these objects are not creations of a mind, but exist independently of thought; the singular Greek terms Plato often uses to name these abstract objects are eidos and idea.) These Forms are eternal, changeless, and incorporeal; since they are imperceptible, we can come to have knowledge of them only through thought. Plato insists that it would be an error to identify two equal sticks with what Equality itself is, or beautiful bodies with what Beauty itself is; after all, he says, we might mistakenly take two equal sticks to be unequal, but we would never suffer from the delusion that Equality itself is unequal. The unchanging and incorporeal Form is the sort of object that is presupposed by Socratic inquiry; what every pious act has in common with every other is that it bears a certain relationship – called ‘participation’ – to one and the same thing, the Form of Piety. In this sense, what makes a pious act pious and a pair of equal sticks equal are the Forms Piety and Equality. When we call sticks equal or acts pious, we are implicitly appealing to a standard of equality or piety, just as someone