The basis for such a claim is an extreme reductionism which, for example, regards human beings as just computers made of elementary particles: “Thus ‘life’ is a form of information processing and the human mind – and the human soul – is a very complex computer program … a person is a computer program which can pass the Turing test.” Tipler acknowledges that an implication of this is that automobiles are “alive”, though not, of course, persons. One can regard the book as pushing physical reductionism to its limit and thus, in my view, exhibiting its chilling implausibility.

The immortality claimed in the title is based on Tipler’s “beautiful postulate” that life, having once come into being, will continue for ever. Of course, all carbon-based life must eventually perish, but intelligence is expected to engineer its own successive embodiments as cosmic circumstances change. Tipler believes that the most favourable case realising this is presented by the collapse of a closed universe subject to a specific future boundary condition which, roughly speaking, requires the causal network of the universe to condense onto a single ultimate point. This is the Omega Point, which Tipler says plays the role of a “physical god” in the new-style religion. In this closing hectic phase, the whole cosmos will become a computer racing at ever increasing speeds, capable of processing an infinite amount of information and so, in Tipler’s view, capable of producing “eternal life”.

The hope of resurrection and immortality resides in the idea that the Omega Point will use its infinite computing capacity to produce emulations of you and me. If we are just programs, that will be sufficient to restore us to “life”. Why should Omega bother to do this? Apparently because it will want to know us, recovering the information from the photons we have emitted in our lifetimes. Tipler acknoweldges but finesses, the problem presented by the degrading of this information due to opactity and decoherence. Will not this act resurrect evil as much as good? Apparently Omega will exercise some discrimination. How do we know that Omega will be benevolent? Apparently because it will realise that microeconomic theory teaches us that if the future value is sufficiently high a strategy of “cheap altruism” is the best to pursue.

Tipler develops his arguments with fantastic ingenuity. The book reads like the highest class of science fiction. General relativity plays an essential role because its infinite phase space will prevent cosmic history being simply a repetitive sequence of returns to the same state. Like all quantum cosmologists, Tipler is driven to place his faith in the contentious (and in my view, implausible) many-worlds interpretation of quantum theory. He presents many clever ideas to develop his argument. One of these is that intelligence will have to take over the whole Universe and then manipulate it so that its terminal collapse takes place in a specifically asymmetric way. This asymmetric collapse will enable gravitational shear energy to become available to run the cosmic computer. The fact that gravitational collapse is a chaotic process, and so is sensitive to small triggers, will enable intelligence to get the cosmic leverage it needs.

Less happy is the claim that many-worlds quantum theory supports the freedom of things to be “otherwise” because there are other parallel worlds in which the same things are actually otherwise. Taken overall, the reliance of the many-worlds theory on the Schrödinger equation alone surely implies a deterministic rather than an open picture of total physical process.

The quality of explanation of the science for the general reader is variable. Sometimes it is very clear but at other times, for instance in the necessarily difficult amount of quantum gravity, a familiarity is assumed which the reader is unlikely to possess. There is a useful “appendix for scientists” to which technical detail has been relegated.

There are many quantitative estimates given, often based on the Bekenstein Bound, limiting the information which can be encoded in a quantum system of given size. Tipler displays astonishing confidence in describing the final stages of the Universe, to a degree which makes the speculations of his quantum cosmology colleagues about the very early Universe appear quite tame and conservative in comparison. The emulation of life can, at the earliest, only start within 10^−n where n = 10¹⁰ seconds of the end of proper time.

Throughout there are references to theologians. These often seem to trade upon verbal parallels which require much more careful evaluation. Yet there is also an interesting degree of parallelism which, for me, serves to show up the thinness of the gospel according to Tipler. It is certainly the case that Thomas Aquinas, and many following him, thought of the soul as the “form”, or information-bearing pattern, of the body, and that they saw the Christian hope of the resurrection as being the reimbodiment of that form by God in a new environment of His choosing.

Yet those in this tradition, among whom I include myself, seek to understand this “pattern” in a richer and more plausible way than is possible if human beings are simply reduced to being finite state machines. The hope of such a resurrection lies not in the curiosity or calculation of a cosmic computer, but in the personal God who cares individually for each of His human creatures.

Tipler’s book is a remarkable speculative tour de force, single-handedly constructing a kind of cosmic Tower of Babel which ultimately proves no more successful than its predecessor on the Plain of Shinar.

Michael Faraday would find a place in anyone’s pantheon of distinguished
scientists. Not only did his deep physical intuition lead him to the great
experimental discoveries of electromagnetic induction and the laws of electrochemistry,
but his ideas about lines of force provided the basis for one of the most
important conceptual innovations in 19th-century physics: the notion of
interaction through the extended medium of a field.

The story of Faraday’s life is a romantic tale, where merit was both
recognised and rewarded. The apprentice bookbinder who learnt science by
the perusal of the works he was binding, became assistant to Sir Humphrey
Davy and eventually the latter’s successor as director of the Royal Institution.

Faraday’s talent was equally for exposition as for discovery. His Friday
evening discourses at the institution drew fashionable crowds. One lady
described his performance as ‘mind addressing mind’. His ingenious and almost
invariably successful use of demonstrations, and his accessibility to young
people, established traditions at the Royal Institution that continue to
this day.

In some ways Faraday was at odds with the science of his time. He viewed
mechanics unfavourably and he had idiosyncratic ideas about inherent powers
in matter and about the ‘conservation of force’. This was doubtless in part
caused by his inability to cope with the mathematical elaboration of Newtonian
physics.

Faraday’s lack of formal education contrasted with the grounding in
the Cambridge Mathematical Tripos that characterised many of his scientific
contemporaries. Augustus de Morgan, the mathematician, said patronisingly
that Faraday was ‘more ignorant of mathematics than any one would imagine’.
The full flowering of electromagnetic field theory would require the mathematical
skill and insight of James Clerk Maxwell.

Geoffrey Cantor suggests that Faraday’s distaste for mechanics may also
partly stem from his metropolitan life and lack of the kind of acquaintance
with industry that shaped someone like James Joule. Cantor also proposes
that Faraday’s notion of inherent powers originated in his theological views.
One of the fascinating things about him, widely known but seldom discussed,
is his lifelong membership of a small nonconformist sect, the Sandemanians.

This tiny movement originated in one of the fissiparous dissensions
of 18th-century Scottish religion. In Faraday’s time, the sect numbered
only about 600, of whom about 100 belonged to the London congregation. The
Sandemanians demanded uniform standards of belief and conduct. They enforced
harmony in their meetings by excluding those who were not in full agreement.
This happened to Faraday in 1844, but he was restored to the fellowship
within a few weeks.

The sect sought to follow the teaching of the Bible, interpreted with
a simple literalism and used as the sole guide. For example, they did not
hold funerals because there is no Biblical instruction to do so. Their manner
was sober and they eschewed any revivalist enthusiasm.

Almost all the great figures of British physical science in the 19th
century, such as Clerk Maxwell, Kelvin and Stokes, were men of deep religious
conviction. They seemed untroubled by the evolutionary storms that raged
around them. However, they belonged in the main to broad religious traditions,
such as Presbyterianism and Anglicanism. Faraday is fascinating because
of his membership of so narrow a denomination. Cantor seeks to explore this
phenomenon. The task is not easy because there is a paucity of relevant
material.

Faraday seldom discussed religion with his scientific correspondents
or made overt references to it in his public discourses. He has often been
spoken of as someone who preserved a separation between his public life
as a scientist and his private life as a Sandemanian believer. One of his
celebrated observations was that ‘there is no philosophy in my religion’.
The tradition of discursive system-building, so congenial in the senior
common room, was foreign to his style.

The picture of a compartmentalised life appears, to some extent, to
be borne out by this book. Cantor does his best to find connections, but
the argument seems rather thin. References to God as the law giver, or to
science as the reading of the book of nature, are really just using the
commonplaces of a religious attitude to creation, and certainly do not betray
any peculiarly Sandemanian slant.

I did not find Cantor’s treatment to be very discriminating in its account
of religious attitudes. He also has a tendency to overplay the hand. I am
not convinced that when Faraday used the word ‘confuse’, the Tower of Babel
was in his mind.

More persuasive is the judgement that ‘both science and Sandemanianism
were strikingly similar responses to his environment, since they both offered
ways of ordering his experience and rendering the world safe’. I wish that
Cantor had been able to shed more light on the mysterious breakdown and
headaches that afflicted Faraday in the 1840s.

Faraday was a man of modesty and integrity, a scientist of great distinction
and a religious believer of deep conviction and surprising simple-mindedness.
He remains something of an enigma. As an essentially private person he would
probably have been content to be so.

John Polkinghorne is President of Queens’ College, Cambridge.

Perhaps the most remarkable paradox of quantum mechanics is that after
more than 60 years of highly successful exploitation of the theory, we still
cannot agree on how it is to be interpreted. The crux of the matter is the
measurement problem: how does it come about that the fitful and elusive
quantum world yields a definite answer on any particular occasion of experimental
inquiry? As Richard Healey rightly says: ‘There is today no fully satisfactory
way of understanding this theory.’ His new book is the beginning of an attempt
to remedy this sad state of affairs.

At its centre lies a distinction between dynamical states and quantum
states (relating to sets of values to be assigned to various dynamical variables,
and thus carrying the ontological significance of the theory) and quantum
states (which are used to calculate probabilities in the familiar way and
which thus articulate the epistomological consequences of the theory). Conventional
quantum theory (particularly in the scheme of interpretation broadly called
after Niels Bohr’s Copenhagen) identifies these two kinds of states. Hidden
variable theories (such as that of David Bohm) make the maximal separation
between the two. Dynamical states, from this view, carry the full classical
information about what is the case. There are a great many of them corresponding
to the much more limited information assigned to a single quantum state.
Healey seeks to set up a scheme which is somewhere between these two extremes.

A second characteristic of his thought is to refuse to assign a privileged
place to observation. (Here, as he acknowledges, he comes quite close to
the ideas of Hugh Everett). Instead, we are given the broad notion of intereactions
possessing some degree of randomness in their character, from which it is
claimed one can select subsets corresponding to the physical acts of preparation
and measurement.

Thirdly, Healey claims a holistic character for this theory. He is anxious
to do so in order to circumvent difficulties with action-at-a-distance,
that arise from the need to get the right results for Alain Aspect’s experiments,
which violated John Bell’s inequality derived from a purely local formulation.
Healey asserts that this holism is due to the fact that ‘the dynamical state
of a compound system does not supervene on the dynamical states of its components.’
Earlier in the book, he acknowledges that his account does not go beyond
that already accessible to conventional quantum theory when it points out
that the wave function of a compound system is not simply the product of
the wave functions its components. It is, therefore, far from clear to me
that any real advance had been made on this front.

I think Healey’s theory might be called the Pretty Obscure Variable
Interpretation. Unfortunately the obscurity does not only relate to the
underlying stochastic dynamics, whose character he acknowledges he is unable
fully to articulate. It extends to the presentation of the material.

A physicist who had come up with an idea of this kind would want to
explain it, in the first instance, by setting down as complete an account
as possible of its application to a simple and typical quantum mechanical
system. The philosopher Healey starts as though this were his intention
also, when he begins to talk about the Stern-Gerlach experiment (measuring
particle spins). However instead of equations and diagrams, we are given
metaphysical discussion, and the mathematics, when it eventually comes,
does so in a flurry of abstract symbolism. This is not the way to help the
reader.

The final chapter frankly describes ‘open questions.’ One of them –
crucial to the success of the task and in many ways the essence of the measurement
problem – is the question of whether what Healey calls M(easurement)-type
systems actually behave like classical systems when they attain a macroscopic
complexity. He also acknowledges that the application of his ideas to quantum
field theory appears ‘fraught with difficulties.’ Healey rather dismisses
this last point, but since all modern accounts of the nature of matter are
quantum field theories, it seems a very significant difficulty to me.

Richard Healey says that ‘Quantum mechanics is a mine of metaphysical
insights, and I hope here at least to have exposed a rich seam.’ Whether
it is gold-bearing remains to be seen.

John Polkinghorne is President of Queen’s College, Cambridge, and his
latest book is Rochester Roundabout: The History of Particle Physics.

METAPHYSICS does not get a good press in an age averse to great issues
and addicted to minute particulars, but I don’t think one can live without
it. Like it or not, implicitly or explicitly, we all take a stance about
the nature of reality and our place within it. Professor Smart’s book addresses
such big questions. He is a philosopher who takes science seriously, to
the point of saying he considers that ‘the best of contemporary theoretical
physicists are more conceptually innovative and imaginative than are professional
philosophers’. But, of course, he adds that nevertheless ‘there are philosophical
questions that philosophers . . . are usually better equipped to discuss
than scientists’.

His book is principally concerned with three grand topics: the nature
of time; the relationship of mind and brain; and the question whether the
existence of the Universe is significant, and if so, of what? Smart’s philosophy
of science is robustly realist. He is not the kind of philosopher who can
only use words like real and true when enclosed in ‘shudder quotation marks’.
He says briskly, ‘A thoroughgoing philosophical scepticism never succeeds,because
without a will to believeof some sort we would be dead.’

Few things seem more fundamental to humanity than its experience of
temporality – the fixed past, the unknown future, and the moving, elusive,
moment of the present, separating the two. Smart believes this to be an
illusion. He is influenced by the space-time picture of relativity, those
frozen chunks of cosmic history through which thread the somewhat thickened
worldlines we misinterpret as our biographies. ‘Surely we must reject the
transitory aspect of time as some sort of conceptual illusion?’ Physicists
will recall that Albert Einstein expressed a similar opinion. Smart is hard
put to it, though, to locate the origin of this widespread misconception.
Of course, thermodynamics comes into it, and there is some philosophical
by-play about ‘indexicals’ (indicators of relationship to utterance), though
the latter seema bit half-hearted to me.

The plain fact is that temporality is not so easily explained away.
Ironically, modern science is moving away from the classical ‘God’s eye’
view of the relativist (contemplating a world of being in which there arerearrangements
but no genuine novelties) and instead is beginning to describe a world of
becoming. Prigogine’s work on non-equilibrium thermodynamics, and the insights
of chaos theory, do not encourage the notion of the future ‘already’ up
there waiting for us, as Smart supposes, but they seem to speak of an openness
of physical process, much more closely akin to direct human experience.

The nature of the relationship of mind and brain has long perplexed
the metaphysicallyinclined. That they are connected is made only too clear
bythe effects of drugs and injury,but the difficulty of bridgingthe chasm
apparently separatingtalk of neural excitations fromtalk of perceiving a
purple patch(let alone wrestling with ametaphysical problem) is verygreat.
Smart is a physicalist andwill have no truck with mentalsubstances. It’s
all there insidethe cranium. He edges out hisbridge by laying emphasis on
‘experiencing’ as the primary category for the discussion and he makes ‘the
additional assertion that experiences are physical processes in the brain’.
Oddly enough, somewhat earlier he has expressed himself asbeing open to
the platonic viewof the nature of mathematics:that it is an exploration
of aninternally existing realm ofideas. It isn’t clear how brainprocesses,
pure and simple,could find a way into such amental territory. It is difficultnot
to think that somethingmore mysterious than neurobiochemistry is involved
here. Of the ineffability of consciousness, Smart says ‘I am inclinedto
feel . . . (it) is merely a symptom of some philosophical confusion.’ Every
calling has its snare, and that of philosophy is to suppose that the answers
to deep questions may be found by just a little extra clarity of definition.

Finally, the biggest metaphysical question of all. We are led to it
via the anthropic principle and notions of many universes, but in the end
the basic issue confronts us. Smart tells us that ‘In some moods the question
of ‘Why does anything exist at all?’ does seem to me . . . to be the profoundest
of all questions, while nevertheless it seems obvious that it could not
possibly have an answer’. Of course, one answer that has appealed to many
is theism. The discussion offered of this option is distinctly desultory.
The only serious account considered by Smart is that of John Leslie’s extreme
‘axiarchism’, in which the principle that value tends to come into existence
is made to do some of the work performed by the classical concept of God.
Interesting as are Leslie’s ideas, and long as their intellectual pedigree
is (he traces them back to Plotinus in the third century), they are scarcely
mainstream theism.

This is an avuncular sort of book, written in a relaxed style. Sometimes
the technicalities come a little too thick and fast; sometimes the scientific
reader may feel that philosophy’s famed capacity for grinding small is too
much in evidence (see the discussion of ‘Alan Border plays an off drive’
on p 116); sometimes the bits of science are not well explained (the accounts
of the electron paramagnetic resonance phenomenon and the Bell inequality
do not quite focus the issues correctly). Yet the book raises very important
questions. I was not persuaded by its answers, but I enjoyed reading them.

John Polkinghorne is President of Queen’s College, Cambridge. His latest
book is Rochester Roundabout: The Story of High Energy Physics (Longman).