This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

Pierre Duhem and Eugenio Randi have investigated the later-medieval history of the problem of whether the existence of more than one world is possible, determining that Aristotle's denial of that possibility was rejected on theological grounds in the second half of the thirteenth century, but it was Nicole Oresme in the mid-fourteenth century who gave the strongest philosophical arguments against the Peripatetic stance, opting instead for Plato's position. For different reasons, neither Duhem nor Randi was able to examine Gerald Odonis' (...) question on the subject. In this text, edited here, Odonis also opposes Aristotle for philosophical reasons and sides explicitly with Plato. Was Oresme aware of Odonis' opinion? (shrink)

The possible existence of extraterrestrial life led in the eighteenth century to a heated debate on the unique status of the human being and of Christianity. One of those who discussed the new scientific worldview and its implications for theology was the Swedish natural philosopher and theologian Emanuel Swedenborg. This article discusses Swedenborg's astrotheological transformation, his use of theological arguments in his early cosmology, and his cosmogony that later on ended up in his use of contemporary natural philosophy in his (...) theology, especially concerning the question of the plurality of worlds. I will first sketch the astrotheology found in his natural philosophical works, and then turn to the astrotheology of his later spiritual teachings. In Swedenborg's works we find teleological arguments and a stress on the universality of the divine creation and Christianity, as well as anthropomorphic descriptions of extraterrestrial life. By reconciling contemporary astronomical ideas, among others the concept of the plurality of worlds, with Christian dogmas, Swedenborg refuted deistic conclusions that Jesus was merely a mortal, while at the same time keeping his belief in the modern astronomical worldview. (shrink)

David Lewis's book 'On the Plurality of Worlds' mounts an extended defense of the thesis of modal realism, that the world we inhabit the entire cosmos of which we are a part is but one of a vast plurality of worlds, or cosmoi, all causally and spatiotemporally isolated from one another. The purpose of this article is to provide an accessible summary of the main positions and arguments in Lewis's book.

Summary The object of this study is to analyse certain aspects of the debate between David Brewster and William Whewell concerning the probability of extra-terrestrial life, in order to illustrate the nature, constitution and condition of natural theology in the decades immediately preceding the publication in 1859 of Charles Darwin's Origin of species. The argument is directed against a stylised picture of natural theology which has been drawn from a backward projection of the Darwinian antithesis between natural selection and certain (...) forms of the design argument. Contrary to the popular image of natural theology as an essentially static, autonomous and monolithic set of presuppositions about the existence of design in nature, the paper underlines the existence of a fundamental divergence of strategies within natural theology, a divergence that, in the case of Brewster and Whewell, can be correlated with the religious cultures to which they most closely belonged. The fact that, in the plurality of worlds debate, their respective positions became mutually exclusive suggests that the fragmented and disordered state of natural theology, only too apparent before the Darwinian impact, was occasioned as much by the ulterior problem of rationalising the excessive space of the astronomers and the excessive time of the geologists as it was by any principle of the uniformity of nature in the biological sphere. The argument is substantiated with particular reference to the breakdown in communication as Brewster and Whewell developed conflicting strategies to expose the ?development hypothesis? that had appeared in Vestiges. Their altercation also reveals a certain conflict of status concerning the conclusions of astronomy and geology which, in turn, suggests that tensions between the physical and life sciences were not peculiar to the period following the publication of Darwin's theory. (shrink)

According to David Lewis, a realist about possible worlds must hold that actuality is relative: the worlds are ontologically all on a par; the actual and the merely possible differ, not absolutely, but in how they relate to us. Call this 'Lewisian realism'. The alternative, 'Leibnizian realism', holds that actuality is an absolute property that marks a distinction in ontological status. Lewis presents two arguments against Leibnizian realism. First, he argues that the Leibnizian realist cannot account for the (...) contingency of actuality. Second, he argues that the Leibnizian realist cannot explain why skepticism about one's own actuality is absurd. In this paper, I mount a defense of Leibnizian realism. (shrink)

ABSTRACT In 1758 in London, Swedish natural philosopher and mystic theologian Emanuel Swedenborg published De Telluribus in Mundo nostro Solari, a treatise on the plurality of worlds and life on other planets. During the seventeenth and eighteenth centuries, these topics formed a heterogenous literary genre which encompassed theology, astronomy, philosophy and satire. In De Telluribus, Swedenborg made detailed claims of communication with extraterrestrial spirits in the afterlife, through which he sought to spread his theology to new audiences. The (...) paper will explore the role of De Telluribus in Swedenborg's career, explain its content and analyse its polarized reception. It will show that De Telluribus combined for the first time the literary codes of two popular genres during the period, namely those concerning the plurality of worlds and the dialogues of the dead. By doing so, the paper revises current scholarly understanding of Swedenborg by showcasing him as a versatile yet ill-fated recombiner of literary genres. More broadly, the paper will shed light upon previously unnoticed eighteenth-century literary interactions along with a wider overview on the reception of themes such as the plurality of worlds, mysticism and satire in Scandinavia and Germany. (shrink)

Astronomers of the first half of the nineteenth century viewed our solar system entirely differently from the way twentieth-century astronomers viewed it. In the earlier period the dominant image was of a set of planets and moons, both of which kinds of bodies were inhabited by intelligent beings comparable to humans. By the early twentieth century, science had driven these beings from every planet in our system except the Earth, leaving our solar system as more or less desolate regions for (...) the most part bereft of intelligent life. This essay traces this extinction and its relation to religious thought, noting the role played in it by Sir John Herschel and especially by William Whewell. The inverse square laws for gravitation, heat radiation, and light receive special attention, as does the question of the relevance of the Christian notions of a divine incarnation and redemption. (shrink)

That life probably exists on other bodies in the universe is now a commonplace. That intelligent life exists elsewhere in the universe--taking for granted its presence on earth--is a widespread hope. Scientific efforts are under way, including space probes, special observations, and broadcast programs, in the systematic search for extraterrestrial intelligence. The question naturally arises whether other human beings are somewhere out there. Fresh avenues of philosophic reflection are opening concerning ethics, theology, and the metaphysics of being human. Imagination has (...) been abundantly working over such issues extraterrestrially. Science fiction has run worlds away from science fact. Surrounded by yearning, fantasy, and popular culture, we need to clarify the intellectual grounds for work on extraterrestriality. The topic of other worlds and other intelligent life is an ancient and recurrent theme in great world cultures, including the Western tradition. (shrink)

Pierre Duhem and Eugenio Randi have investigated the later-medieval history of the problem of whether the existence of more than one world is possible, determining that Aristotle's denial of that possibility was rejected on theological grounds in the second half of the thirteenth century, but it was Nicole Oresme in the mid-fourteenth century who gave the strongest philosophical arguments against the Peripatetic stance, opting instead for Plato's position. For different reasons, neither Duhem nor Randi was able to examine Gerald Odonis' (...) question on the subject. In this text, edited here, Odonis also opposes Aristotle for philosophical reasons and sides explicitly with Plato. Was Oresme aware of Odonis' opinion? (shrink)

A commentary on David Lewis's /On the Plurality of Worlds/.

These selections from Le système du monde, the classic ten-volume history of the physical sciences written by the great French physicist Pierre Duhem (1861-1916), focus on cosmology, Duhem's greatest interest. By reconsidering the work of such Arab and Christian scholars as Averroes, Avicenna, Gregory of Rimini, Albert of Saxony, Nicole Oresme, Duns Scotus, and William of Occam, Duhem demonstrated the sophistication of medieval science and cosmology.

By the middle of the nineteenth century, the opinion of science, as well as of philosophy and even religion, was, at least in Britain, firmly in the camp of the plurality of worlds, the view that intelligent life exists on other celestial bodies. William Whewell, considered an expert on science, philosophy and religion, would have been expected to support this position. Yet he surprised everyone in 1853 by publishing a work arguing strongly against the plurality view. This (...) was even stranger given that he had endorsed pluralism twenty years earlier in his contribution to the Bridgewater Treatises. In this paper I show that the shift in Whewell’s view was motivated by three factors: the influence of Richard Owen’s theory of archetypes on Whewell’s view of the argument from design, and Whewell’s perception of the need to strengthen such arguments in light of evolutionary accounts of human origins; important developments in his view of philosophy and his role as a scientific expert; and new findings in astronomy. An examination of the development of Whewell’s position provides a lens through which we can view the interplay of theology, philosophy and science in the plurality of worlds debate.Keywords: William Whewell; Plurality of worlds; Natural theology; Analogies; Archetypes; Conjectures; Evolution. (shrink)

This book is an explication and defense of the author's modal realism. There are possible worlds and individuals, he says, different from the possibles realized in this world of ours. The reality of the many possibilities is a hypothesis needed for explaining the representational character of our language, as when we say that there might be talking donkeys, though there are none. It is the reality of these possibles, as worlds and individuals, that Lewis defends.