One of the first books to address what has come to be known as the philosophy of cosmology, Universes asks, "Why does the universe exist?", arguing that the universe is "fine tuned for producing life." For example, if the universe's early expansion speed had been smaller by one part in a million, then it would have recollapsed rapidly; with an equivalently tiny speed increase, no galaxies would have formed. Either way, this universe would have been lifeless.
Are we in imminent danger of extinction? Yes, we probably are, argues John Leslie in his chilling account of the dangers facing the human race as we approach the second millenium. The End of the World is a sobering assessment of the many disasters that scientists have predicted and speculated on as leading to apocalypse. In the first comprehensive survey, potential catastrophes - ranging from deadly diseases to high-energy physics experiments - are explored to help us understand the risks. One (...) of the greatest threats facing humankind, however, is the insurmountable fact that we are a relatively young species, a risk which is at the heart of the 'Doomsday Argument'. This argument, if correct, makes the dangers we face more serious than we could have ever imagined. This more than anything makes the arrogance and ignorance of politicians, and indeed philosophers, so disturbing as they continue to ignore the manifest dangers facing future generations. (shrink)
Carter’s anthropic principle reminds us that intelligent life can find itself only in life-permitting times, places or universes. The principle concerns a possible observational selection effect, not a designing deity. It has no special concern with humans, nor does it say that intelligent life is inevitable and common. Barrow and Tipler, who discuss all this, are not biologically ignorant. As argued in "Universes" (Leslie, 1989) they may well be right in thinking that "fine tuning" of force strengths and particle masses, (...) without which life would be impossible, proves the reality of God or else of multiple universes plus observational selection. (shrink)
The cosmos exists just because of the ethical need for it We, and all the intricate structures of our universe, exist as thoughts in a divine mind that knows everything worth knowing. There could also be infinitely many other universes in this mind....It may be hard to believe that the universe is as Leslie says it is--but it is also hard to resist his compelling ideas and arguments.
This compelling study of the origins of all that exists, including explanations of the entire material world, traces the responses of philosophers and scientists to the most elemental and haunting question of all: why is _anything_ here—or anything _anywhere_? Why is there something rather than nothing? Why not nothing? It includes the thoughts of dozens of luminaries from Plato and Aristotle to Aquinas and Leibniz to modern thinkers such as physicists Stephen Hawking and Steven Weinberg, philosophers Robert Nozick and Derek (...) Parfit, philosophers of religion Alvin Plantinga and Richard Swinburne, and the Dalai Lama. The first accessible volume to cover a wide range of possible reasons for the existence of all reality, from over 50 renowned thinkers, including Plato, Aristotle, Aquinas, Descartes, Leibniz, Hume, Bertrand Russell, Stephen Hawking, Steven Weinberg, Robert Nozick, Derek Parfit, Alvin Plantinga, Richard Swinburne, John Polkinghorne, Paul Davies, and the Dalai Lama Features insights by scientists, philosophers, and theologians Includes informative and helpful editorial introductions to each section Provides a wealth of suggestions for further reading and research Presents material that is both comprehensive and comprehensible. (shrink)
Suppose various observers are divided randomly into two groups, a large and a small. Not knowing into which group anyone has been sent, each can have strong grounds for believing in being in the large group, although recognizing that every observer in the other group has equally powerful reasons for thinking of this other group as the large one. Justified belief can therefore be observer-relative in a rather paradoxical way. Appreciating this allows one to reject an intriguing new objection against (...) Brandon Carter's 'doomsday argument'. Carter encourages us to doubt that we are among only the first hundredth, say, or first millionth, of all humans who will ever have existed. He thereby reinforces whatever reasons we may have for suspecting that, unless we take great care, the human race will not survive long. Admittedly his argument is weakened if our world is indeterministic, so that there is no suitably guaranteed 'fact of the matter' of how many humans will ever have existed. But even then, it can caution us against believing that a lengthy future for humankind 'is as good as determined'. Of all the objections the argument has yet faced, the new one is the most interesting. (shrink)
Do our lives have meaning? Should we create more people? Is death bad? Should we commit suicide? Would it be better if we were immortal? Should we be optimistic or pessimistic? Life, Death, and Meaning brings together key readings, primarily by English-speaking philosophers, on such 'big questions.'.
Cosmologists using the Anthropic Principle claim that if our universe had been much different then nobody would exist to observe it. This may become explanatory when one accepts the actual existence of multiple "universes": gigantic, largely or entirely separate systems having very varied properties. Ian Hacking has urged, though, that an Inverse Gambler's Fallacy is committed during many attempts to formulate anthropic explanations. Besides disagreeing with him, the paper makes several further points in support of such explanations, in particular against (...) the background of the Inflationary Universe. (shrink)
Our world seems fine tuned in life-permitting ways. If the cosmos contains many universes, only the appropriately tuned ones can be seen by living beings. An alternative is that God acted as Fine Tuner. We might account for God in terms of an eternally powerful ethical requirement that God exists, rejecting J. L. Mackie's judgment that absolute ethical requirements are incredibly queer. Mackie viewed such requirements as logically possible, so if they were absent then this would seem a matter of (...) synthetic necessity. Again, if they existed then their creative effectiveness would, Mackie thought, be logically possible. Their actual ineffectiveness would thus involve a further synthetic necessity. Theists could maintain that the synthetic necessities were instead ones making ethical requirements real and creatively powerful. Yet why, then, would there exist anything but divine knowledge of everything worth knowing? A spinozistic answer is that such knowledge is all that exists. (shrink)
Physical force strengths, particle masses, the early cosmic expansion speed and many other factors seem "fine tuned for life". Had they been slightly different, life’s evolution would have been impossible. The situation resembles catching a fish with an apparatus unable to catch ones slightly differently sized. One explanation is that the lake contains fish of many different sizes: multiple universes with randomized characteristics, most of them unobservable because observers cannot evolve in them. Another is that God created a fish of (...) the right size, a universe able to generate observers. The article defends these explanations against numerous ingenious objections. (shrink)
If it survives for a little longer, the human race will probably start to spread across its galaxy. Germ warfare, though, or environmental collapse or many another factor might shortly drive humans to extinction. Are they likely to avoid it? Well, suppose they spread across the galaxy. Of all humans who would ever have been born, maybe only one in a hundred thousand would have lived as early as you. If, in contrast, humans soon became extinct then because of the (...) population explosion you would have been 'fairly ordinary'. Roughly ten per cent of all humans would have been your contemporaries. Now (as the cosmologist Brandon Carter saw to his dismay) a scientific principle tells us not to treat observations as highly extraordinary when they could easily be fairly ordinary. How to apply the principle is controversial, yet it seems we can safely conclude that humanity's chances of galactic colonization cannot be high. Still, we should work to make them as high as possible, resisting those philosophers who argue that human extinction would be no tragedy. (shrink)
David Hume's greatness depends in large part on how his writings hint at beautiful and coherent theories which are recognizably Humean despite their divergences from the untidy originals. Now, perhaps the clearest vision of a contradiction–free Platonic Form of Hume was had by J. L. Mackie; he described it in such masterpieces as The Cement of the Universe, Ethics: Inventing Right and Wrong, and The Miracle of Theism. How successful is this last in its attack on theism? I shall discuss (...) Mackie's case against theism of a Platonic or Neoplatonic type which replaces ‘God as a person or mind or spirit’ by a more abstract Creative Force or Principle. Mackie sees in it a ‘a formidable rival’ to any theism treating of a divine being; ‘if you demand an ultimate explanation, then this may well be a better one’ . But, his chapter thirteen contends, it fares badly in competition with an atheistic, naturalistic approach. (shrink)
A recent book of mine defends three distinct varieties of immortality. One of them is an infinitely lengthy afterlife; however, any hopes of it might seem destroyed by something like Brandon Carter's 'doomsday argument' against viewing ourselves as extremely early humans. The apparent difficulty might be overcome in two ways. First, if the world is non-deterministic then anything on the lines of the doomsday argument may prove unable to deliver a strongly pessimistic conclusion. Secondly, anything on those lines may break (...) down when an infinite sequence of experiences is in question. (shrink)
Abstract An argument originated by Brandon Carter presents humankind's imminent extinction as likelier than we should otherwise have judged. We ought to be reluctant to think ourselves among the earliest 0.01 %, for instance, of all humans who will ever have lived; yet we should be in that tiny group if the human race survived long, even at just its present size. While such reasoning attracts many criticisms, perhaps the only grave one is that indeterminism means there is not yet (...) any firm, theoretically predictable fact of how long the human race will survive. This, though, might not save Everett's many?worlds theory from a variant on Carter's point. Everett seemingly pictures observers as splitting into ever more versions, which explains away all apparent indeterminism; but then, absurdly, all except a vanishingly tiny proportion of one's versions would come into existence near one's death, outweighing all apparent evidence that death was not imminent. The need to avoid such a result severely constrains Everett?type theories. We need theories in which observer?versions diverge without increasing their numbers in any straightforward way. (shrink)
The paper develops a Platonic and Spinozistic metaphysics. With an unprovable yet absolute necessity, the cosmos exists just because of the ethical need for it. We, and all the intricate structures of our universe, exist as intricately structured thoughts in a divine mind. This mind could contain infinitely many other universes as well, and minds of the same kind could exist in infinite number. Evidence for this is supplied by the finely tuned orderliness of our universe, and by the sheer (...) fact that any universe exists. (shrink)
Would Earth be sadly underpopulated if all life on it had died? I shall argue for a Yes, against two main groups. In the first are those who say that life's absence could not be sad, a pity, something less than ideal, because there would be nobody to be sad about it. The second group maintains that life's absence would be preferable to its presence since living can be nasty.
By ‘a blank’, let us mean a situation including no actual existents: nothing beyond such platonic realities as that three groups of five apples, were there to exist such groups, would contain fifteen apples in total. Now, why is there a world and not a blank?