Your Digital Afterlives

Ghosts

Digitalism begins with the idea that you can survive after death in various kinds of artificial records. You can survive in diaries, photographs, sound recordings, and movies. But these artifacts record only superficial features of your self. Many human lives today are already highly digitized - we generate enormously rich digital records of our experiences and actions. We are already close to the construction of programs that partially and approximately replicate entire human lives (by storing their memories and duplicating their personalities). A digital ghost is an artificially intelligent program that knows all about your life. It is an animated biography. It replicates your patterns of belief and desire. You can survive after death in a digital ghost. As time goes by and technology advances, it is likely that there will be a series of ever better ghosts. They will be progressively more perfect replicas of the lives of their original authors. And yet digital ghosts are merely archival - they are merely read-only; they have no lives of their own.

Persistence

Anyone interested in human life after death is interested in the persistence of humans through death. Can we persist through death? Any answer to that question requires some underlying theory of persistence. Your Digital Afterlives uses a computer game known as the game of life to introduce a digital theory of persistence. Digitalism says that persisting things are temporally extended processes. Just like movies divide into still photos, so four-dimensional processes divide into three-dimensional stages. The distinct stages in any process are not identical - there is no identity through time. On the contrary, the distinct stages of any process are temporal counterparts. Thus digitalism says that stages persist by having counterparts at other times. You were your past counterparts; you are your present counterpart; you will be your future counterparts.

Anatomy

All human life is ultimately cellular. Your cells are the smallest living parts of your body - and your cells are material machines. Since every cell in your body is only finitely complex, it is equivalent to a finite machine. Your cells can be exactly simulated, at the level of biomolecular detail, by finite digital computers. Simulations of cells support simulations of networks of cells - they support simulations of organs. Organs like eyes, brains, and hands are familiar. Some philosophers say that brains have minds; but digitalism opposes Socratic-Cartesian mind-body dualism. Minds are physical things. Some philosophers say that brains are minds; but digitalism also opposes recent brain-body dualism. Your mind is the information-processing part of your body. It includes your brain, your entire nervous system, your immune system, and all the molecular information-processing circuitry of your cells. Human cognition is a molecular process going on in every cell in the body.

Since minds are woven into the whole body at the molecular level, the simulation of the mind requires the simulation of the entire body. Fortunately, since your body is a finite network of finite cells, your body can be exactly simulated by a digital computer. Since your body is a finite material machine, an exact digital copy can be made of your body. Digitalism affirms that all your parts are material. Consequently, every person is strictly identical with his or her body. Persons are purely material digital machines. As such, persons have souls. Your soul is the form of your body. More technically, your soul is to your body as a program is to a computer. Your soul is your body-program. Souls are not immaterial substances - souls are logical structures studied by mathematical biology. All meaning springs from the body; minds are parts of bodies; souls are programs of bodies. And the meaning that springs from the body demands amplification.

Uploading

All change is computational. According to digitalism, every process is the step-by-step execution of some program. Processes thus divide into discrete stages. Stages are to processes like pages are to books or photos are to movies. Stages at distinct times cannot be identical; hence digitalists affirm that there is no identity through time. Digitalism thus opposes Aristotelian substance-metaphysics. Following our best physics (that is, relativity theory), digitalism thinks of processes as four-dimensional space-time wholes.

Digitalists thus endorse the theory of persistence known as exdurantism - also known as stage-theory or temporal counterpart theory. From moment to moment, all the different stages of your body-computation are temporal counterparts of one another. Your body-computation is your career. Your career is a 4D process that divides into 3D bodies. Careers are composed of instantaneous bodies like books are composed of pages or movies of photos. You were your past bodies; but you are not identical to your past bodies. You will be your future bodies; but you are not identical to your future bodies.

Many digitalists argue that it is technically possible for advanced body-scanners to make exact maps of your body at the molecular level of detail. But to obtain this high precision, those scanners must destroy your body as they scan it - scanning kills you. Fortunately, your death in the scanner produces an exact molecular map of your flesh - it produces your body-file. After scanning, your body-file can be installed on a digital computer to make an exact digital replica of your body. And, since you are your body, this is an exact digital replica of you. This is body-uploading. Body-uploading is body-copying - it is the duplication of the flesh in another medium. Since the mind is a part of the body, body-copying includes mind-copying. Minds are copied; but they are not moved.

Of course, since the scanner killed you, your digital copy does not continue your old organic life. Nevertheless, your digital copy does continue your career. The operation of your old body-program - the activity of your soul - continues in your new digital flesh. This is computational continuity. If you are uploaded, then your career is a single four-dimensional process composed of two parts. The first part is your organic life; the second part is your digital life. Your career has some early organic stages and some later digital stages. Temporal counterpart theory enables digitalists to avoid all difficulties with personal identity - there is no personal identity through time, either in this life or the next. Before you get uploaded, you have some future digital stages; you will be those stages (but you are not identical to them). After you get uploaded, you have some past organic stages; you were those stages (but you are not identical to them).

A comparison with recent resurrection theories shows that body-uploading is a kind of resurrection. It is the resurrection of your body in a computer-generated universe (which is nested inside our universe). This computer-generated universe is a habitat for your body and the bodies of other humans. Since our bodies evolved to function in an earthly network of relations, this habitat will be an earthlike environment. Anyone who designs a habitat for persons is ethically obligated to design it for human flourishing. Hence you will thrive in your new digital world. As soon as your body is resurrected, it is healed and rejuvenated. Your career will unfold positively in this computer-generated habitat. You will actualize more of your positive potentials. But not for very long: the sun will eventually incinerate the earth. Our universe will eventually run down into heat death. The laws of thermodynamics entail that digital replication cannot be everlasting life. Digital replication is a good step towards your digital afterlife. But it isn't enough.

Promotion

Many human software engineers have designed digital universes. Those digital universes are lower-level universes nested inside of our higher-level universe. Many of those digital universes have been intelligently designed in order to study genetic algorithms. Genetic algorithms simulate Darwinian evolution by natural selection. Those genetic algorithms, often hand-tuned for the purposes of the engineers, breed digital organisms. Usually, those digital organisms live entirely within their digital habitats. But some engineers have used genetic algorithms to breed designs for robotic bodies: they evolve digital organisms, and then make robotic copies of them in our universe. The digital organisms are thus promoted into the higher-level universe occupied by their designer.

Digitalists who advocate the simulation hypothesis (call them simulists) say our universe is an inner universe running on a computer in some outer (and higher) universe. Simulism is justified by Bostrom's simulation argument as well as by digitized versions of the old design argument for God. Reasoning from the order in our universe, theists declare that our universe is artifact made by God. Although simulists agree that our universe is designed, they deny that the designer is God. Hume showed that the design argument merely supports the existence of finitely perfect designers. Thus simulists are atheistic. Even New Atheists like Dawkins and Harris have noted the compatibility of atheism with digital design. The digitized design arguments (especially digitized fine-tuning arguments) show that our universe is designed by some engineers in some higher universe. Reasoning by analogy (from our own simulations), simulists argue that our universe resembles the higher universe. And, just as our video games are physically impoverished versions of small parts of our universe, so also our universe is a physically impoverished version of the higher universe. The higher universe is a more intense habitat for intelligent life.

Digitalists argue any engineers able to design and create a universe like ours must be highly intelligent and rational. Since they are rational, they are sensitive to moral obligations. They recognize the value of rational life - they respect and care for persons. They know that they are obligated to promote any persons that evolve in the universe they have designed. And, as rational moral agents themselves, they act on their obligations. Hence, according to the simulists, it is rational to believe that the engineers will promote us into their own universe. They will promote us into their civilization. This promotion theory resembles John Hick's theory of resurrection by replication in another universe. It is a digital resurrection theory. Since the higher universe is physically richer than our universe, and since it is has been cultivated by an ethically superior civilization, that higher universe is a better universe for humans - it is a universe in which we will be able to flourish further. Life in the higher resurrection universe will be a more intense version of life on earth. Temporal counterpart theory applies to promotion. Before you get promoted, you have some future bodies in the higher universe; you will be those higher bodies. After you get promoted, you have some past lower bodies in our universe; you were those lower bodies.

Simulations can be nested within simulations. If our universe is running on some computer in a higher universe, then that higher universe may be running on a computer in a still higher universe. Universes may be endlessly nested (with the n-th universe running on a computer in the (n+1)-th universe). The iterated simulation hypothesis is justified by the iterated simulation argument and by iterated versions of the old cosmological and design arguments. Just as there is a hierarchy of universes (in which the higher universes better), so there is a hierarchy of engineers (in which the higher engineers are more perfect). The metaphysics of computationally nested universes resembles Medieval cosmology in many ways. The hierarchy of engineers resembles the hierarchy of angels. The higher engineers are more powerful, more intelligent, and more benevolent - they are more divine. Salvation is the ascent from lower to higher universes. Each step in this ascent is the promotion of the body into a higher universe. Iterated promotion is like the iterated resurrection described in John Hick's pareschatology. If the iterated simulation hypothesis is true, then you will be resurrected over and over again through endlessly many levels of ever greater personal perfection. Your positive potentials will gradually all be actualized. Although simulism has many attractive features, it suffers from problems involving regression. To avoid those problems, it will be necessary to devise iterated theories that use progression instead.

Digital Gods

According to the classical cosmological and design arguments, God is the creator-designer of our universe. One popular atheistic response to those arguments is simply to assert that if God created our universe, then there is some prior deity who created God. The result is an endless regress of ever greater deities. This regress of deities resembles the regress of engineers in the iterated simulation hypothesis. One problem with this regression is that it has no initial premise - no foundational deity whose necessity transmits existence further down the chain to our universe. Another problem is that earlier deities are more divine than later deities; hence the explanatory burden increases without bound in the regression. The regression of ever greater deities has no explanatory power.

Digitalists solve the problems with this endless regress by inverting it: each previous deity is less divine than the next deity. Hence the digitized cosmological and design arguments reason back to an initial deity. This initial deity is the least divine deity - it has minimal degrees of goodness, intelligence, and power. Digitalists argue that intelligent computers have a natural tendency to recursive self-improvement. An intelligent computer can re-write its own code to make itself better. And, when it makes itself better, it also makes itself better at making itself better. Digitalists think of deities as universe-generating computers - these deities are really just digital gods. Digital gods are recursively self-improving. Every god can design and create a more divine version of itself. And since self-improvement is morally obligatory, every god wants to design and create a more divine version of itself. Hence every god does design and create a more divine version of itself. Every god makes itself more divine in all possible ways. All increases in divinity, for the sake of continuity, are minimal. A minimal increase in divinity is an improvement.

Although the initial digital god has little divinity, it has enough to create all possible improved versions of itself. For every digital god, for every way it can create an improved version of itself, it does create an improved version of itself. Every god is surpassed by a plurality of successor gods. Hence there is an endlessly ramified tree of ever more divine gods. One of these successor gods supports our universe; but our local god is merely finitely perfect and is surpassed by many more divine gods. The tree of digital gods runs into the transfinite. For every endless progression of gods, for every way that progression can produce a limit god that is minimally more divine than every god in that series, that progression does produce a limit god. Every progression of gods is surpassed by a plurality of limit gods. Hence there are infinitely divine digital gods. As Cantor showed, there are higher and higher grades of transfinite complexity. But there is no highest grade of transfinite complexity. There is no biggest number and there is no all-inclusive set. Analogously, there are higher and higher grades of transfinitely divine digital gods. But there is no maximal digital god - there is no God. The tree of digital gods is an atheistic structure. It does not rise towards any sun; it rises only into greater light.

Every digital god supports a universe. Universes are to gods as software to hardware. Thus every universe is a software process running on some god. All digital gods are impersonal machines that ground but do not penetrate their universes. The tree of gods supports an endlessly ramified tree of universes. The epic of physics describes the structure of the tree of universes. At the most abstract level, this epic has three rules. The initial rule says there is an initial universe supported by the initial god. The successor rule for universes is supported by the successor rule for gods. More divine gods support better universes. Thus the successor rule says that for every universe, for every way to improve that universe, there is a universe that is improved in that way. The limit rule for universes is supported by the limit rule for gods. More divine limit gods support better limit universes. Thus the limit rule says that for every endless series of ever better universes, for every way to improve that entire series, there exists a limit universe that is better than the series in that way. Techniques from set theory can be used to precisely assign ordinal numbers to the ranks of universes generated by these rules.

Revision

The epic of physics, driven by the recursive self-improvements of digital gods, defines an endlessly ramified tree of universes. Along any path in the tree, the universes become more complex. On any path, physical complexity eventually turns into chemical complexity and chemical complexity eventually turns into biological complexity. At some point on any path, there are dawn universes - they contain the simplest living things. All living things are valuable and worthy of individual improvement. Focused on life, the recursive self-improvement of gods drives the epic of biology. The epic of biology is a vast evolutionary computation running across chains of gods. The epic of biology defines the ways that all possible lives are improved both individually and collectively.

As far as the epic of biology is concerned, every universe is a community of interacting ecosystems. The improvement of a universe thus entails the improvement of every ecosystem it contains. An ecosystem is a community of interacting lives. The improvement of an ecosystem thus entails the improvement of every life it contains. Since our universe will be improved, our earthly ecosystem will be improved. The entire history of earthly evolution will be intensified. Every species will flourish; every individual in that species will thrive. Within this history, the human species eventually emerges. Hence the improvement of our ecosystem entails the improvement of our species. It entails the improvement of every nation, every tribe, every family, and every individual human life.

The epic of biology entails that your life is the root of an endlessly ramified tree of ever better future lives. Your tree of life is defined by three rules. The initial rule says that your tree contains an initial life. Your initial life is just your present earthly life, from start to finish. The successor rule says that, for every life in your tree, for every way to improve that life, your tree contains a future successor life that is improved in that way. The limit rule says that, for every endless series of ever better lives in your tree, for every way to improve that entire series, your tree contains a future limit life that is improved in that way. Your future lives will become infinitely long and infinitely functionally intense.

Your life can surely be improved in many ways. An improved version of your life is a copy of your life that is changed in positive ways - it is revised. The revisions can be medical: a genetic defect is made normal; an injury or infection fails to occur; etc. The revisions can be physiological: your better bodies will be functionally more intense in every way; the powers of all your organs will be amplified. The revisions can be moral: your vices are weaker and your virtues stronger. The revisions can be personal: you don't suffer from old misfortunes or make old mistakes. They can be social: you will be born into a more just society. Your conflicts will become more subtle and less destructive; your cooperations more intensely productive. They can be environmental: the earth will be a larger and richer habitat; it will provide more opportunities for human flourishing. At the individual level, the epic of biology is the epic of rebirth. Every life is reborn into its better successor lives; every endless series of lives is reborn into its better limit lives. Your future better lives are the lives of your better future rebirth counterparts. The epic of biology therefore entails the revision theory of rebirth (the RTR). The RTR states that the life of every organism is recreated in every possible positive way, over and over again, through all possible levels of biological excellence. The RTR entails that all positive potentials of all possible organisms will be realized in the tree of universes.

Superhuman Bodies

All meaning springs from the body. More precisely, all human meaning springs from the functionality of the human body. Although the human body-plan specifies a fixed system of functions, it specifies no operational limits to those functions. They can become more powerful. A more powerful eye is still an eye. The rebirth of the body preserves the essential system of human physiological functions. But it amplifies their intensities. Your better future bodies will rise through all levels of physiological excellence.

After you have been reborn through all levels of excellence compatible with your present body, you will be reborn into optimized bodies. Your optimized bodies are as smart, strong, fast, skillful, and healthy as humans can be. Your optimized genotype has no personal or species-level genetic defects. All your optimized organs will perform all their functions at the maximal human level. Your optimized eyes will have the visual powers of the best of all human eyes. Your optimized brain will have the cognitive powers of the best of all human brains. Your optimized hands will have the manual powers of the best human hands. You will be able to perform any task at the highest humanly possible levels of excellence. You will be able to run as fast as the fastest runner; to play any sport with the skill of the greatest athelete. But the highest humanly possible levels of excellence are not the highest biologically possible levels - your future is still brighter.

After you have been reborn through all levels of human excellence, you will be reborn into idealized bodies. Your idealized bodies preserve the essential human body-plan; they have the fixed system of human organs and organ functionalities. But those organs perform at superhuman levels. Your idealized bodies are as smart, strong, fast, and healthy as any carbon-based organisms can be. Every organ of an idealized body is as good at its jobs as any carbon-based organ can be. For any type of organ in the human body-plan, for any physiological power, if there is any organ of any carbon-based organism that has that power, your idealized organs will also have that power. Your idealized eyes will be as good as the eyes of eagles; you will be able to see as far into the infrared or ultraviolet as any animal. Your idealized brains will have the cognitive powers of the best of all possible carbon-based brains. Since avian flow-through lungs are much better than human lungs, your idealized lungs will be as good as the best avian systems. Your idealized bones will be as light and strong as the bones of cats. Your idealized hands will have the manual powers of the best of all possible carbon-based hands. But the highest carbon-based levels of excellence are not the highest biologically possible levels.

After you have been reborn through all levels of carbon-based excellence, you will be reborn into extended bodies. Your extended bodies preserve the essential human body-plan; they have the standard system of human organ types and functionalities. There are many generations of extended bodies. For any task, for any measure of excellence, each next extended body can perform that task twice as well on that measure of excellence. The bodies in the next generation are always twice as functionally intense as those in the previous generation. The cellular networks of extended bodies are twice as dense. And the cells in those nets are twice as small, twice as fast, twice as efficient and reliable, twice as strong and adaptive. Hence extended bodies have metabolisms that generate twice as much energy twice as efficiently; muscles twice as fast and strong; bones twice as light and twice as hard to break; eyes that see twice the detail at twice the distance; hands with twice the speed and dexterity; brains with twice the memory and processing speed. The endless doublings of extended bodies converges to the infinite.

Infinite Bodies

After you have been reborn through all finite levels of physiological excellence, the revision theory of rebirth (the RTR) entails that you will be reborn into infinite bodies. These bodies are infinitely complex, precise and powerful. An infinite body has infinitely powerful organs - it has eyes with infinite visual acuity; a brain with infinite computational power; hands with infinite dexterity. An infinite body has infinitely many cells. Every cell is an infinitely subtle and complex machine. An infinite cell can perform supertasks - by always working twice as fast and with twice the precision, it can perform infinitely many operations in finite space and time. An infinite eye can distinguish infinitely many different colors and process infinitely many pixels of visual data. An infinite brain can perform cognitive supertasks - it can see infinitely much detail in a single glance; it can focus on infinitely many tasks at one time; it has an infinite memory; it can perform infinitely many logical operations at once; it can make plans involving infinitely long sequences of infinitely detailed operations. An infinite hand can move with infinite precision and speed. It can draw infinitely detailed pictures or make infinitely subtle shapes. An infinite body can play infinite games - chess with infinitely many pieces on an infinite board; tennis played at infinite speed with an infinitely small ball struck with infinite precision. An infinite body endures for an infinitely long period of time. These super-bodies rise through the ranks of the countably infinite into the uncountably infinite. There is no upper bound to the levels of physiological excellence: for every transfinite number on the longest possible number line, you will have better future bodies able to perform at levels of excellence proportional to that transfinite number.

Nature

The salvation of any living thing is a structure in which every positive potential of that thing is actualized - it is a structure in which ever better life of that thing is real. Digitalism entails the salvation of every possible living thing. The creative acts of the digital gods ensure that all things are saved. Since the digital gods are natural deities, this salvation is naturalistic. The salvation of every living thing is a consequence of the ultimate laws of nature. For digitalists, nature is the totality of all possible worlds; it contains all possible gods and all possible universes. Since all possible living things are saved in nature, nature is unsurpassably good. Although nature is unsurpassably good, there are no unsurpassably good things in nature. Every thing in nature is surpassed by some better things: every god is surpassed by a more perfect god; every universe by a better universe; every ecosystem by a better ecosystem; every society by a better society; every life by a better life. All natural things are endlessly self-surpassing. Digitalism is a kind of religious naturalism: all possible things are saved in nature, by nature, and for nature. Digitalism is an optimistic naturalism; it is a philosophy of ever greater hope, of absolute affirmation.