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Our future, our universe, and other weighty topics

Sunday, September 22, 2013

Things We Can Never Be Certain About

Humans do not like uncertainty, and people tend to feel they are certain about some things even though they really lack certainty about such things. Moreover, there is a large and important list of things that we can never be certain about, no matter what knowledge and experiences we may have in the future, before or after our deaths. Below are some of the more interesting items on this list.

cosmic ignorance

We can never be certain that we are alone in the universe

It is easy to imagine how we might have some experiences that would confirm that there is other intelligent life in the universe, such as the appearance of a giant spaceship in orbit around the Earth. But there are no experiences we could ever have that could justify certainty that man is alone in the universe. If the universe were small and easy to explore, we could imagine how we might have experiences that might justify certainty about our uniqueness in such a universe. You can imagine, for example, a ten-year spaceship voyage that might visit and explore all solar systems in such a tiny universe, verifying that none had intelligent life except Earth. But our universe is vastly too big for even one percent of it to be explored by a single planet in a million year time frame. Even if one imagines a vast fleet of space-warp starships that could travel instantaneously anywhere in the universe, it would take hundreds of millions of years or billions of years for such a fleet to explore all of the solar systems in our actual universe of billions of galaxies, most containing billions of stars (which gives you a totality of something like 100,000,000,000,000,000,000,000 stars capable of supporting life). By the time such a fleet returned to its home planet, it would then still not be certain that the home planet was the only planet with intelligent life, because there would still be the possibility that intelligent life had evolved on some planet during the millions of years that such a universe-spanning mission was undertaken.

We can never be certain that a being we encountered in this life or the next is the Supreme Being of the universe

It is entirely possible that we might one day encounter some mysterious Higher Power, a mind far greater than ours with supernatural power. Such a being might appear some day in the sky, or we might see such a being when we experienced some kind of life after death. For example, to follow a scenario suggested by near-death experiences, after you die you might travel through some tunnel and find yourself in some radiant heaven-like surroundings where you meet relatives you knew before they died. You might then see some glowing figure or light, and might be told by others that this being is God.

However, while you might be justifiably certain that such a being is some Higher Power with superhuman knowledge and power, you could not justifiably be certain that such a being was actually the Supreme Being of the universe. For there would always be the possibility that there existed some other being unobserved by you who had even more power and knowledge than this Higher Power you encountered, and who existed before that being.

Now you might think that you could gain certainty by talking to this Higher Power, and asking him if he was the Supreme Being of the universe. If such a Higher Power answered affirmatively, would that not justify certainty that this Higher Power was the Supreme Being of the universe?

No, it wouldn't. The reason is simply that there would always be a reasonable chance that this Higher Power was mistaken if it asserted that it was the Supreme Being of the universe. There might still be some higher, more powerful, and wiser being unknown to this Higher Power, and that being might be the Supreme Being of the universe.

We can never be certain that there does not exist some deity

Much as atheists might like to imagine some experiences that might prove there is no deity, there is no possibility of such experiences. We might conceivably find some evidence that might completely undermine faith in earthly revealed religions, but such evidence would at worst merely show that the most popular conceptions of God were in error. They could never disprove that some type of deity exists. Even if we were to explore the universe and find that it was an endless ocean of sorrow, pain, and confusion, we could never disprove the idea that it was created by some deity of limited power.

We can never be certain that matter exists independently of our perceptions

In his philosophical masterpiece A Treatise Concerning the Principles of Human Knowledge, the philosopher George Berkeley argued powerfully that all that really exists is perceptions, and that matter exists only to the extent that it is perceived by minds. We can never be certain that Berkeley wasn't correct. The only way to prove that matter can truly exist independently of mind would be to kill everyone in the universe, and then verify that the universe was still around. But that would be impossible, because if everyone in the universe died, there would be no one around to do such a verification.

We can never be certain that we will live forever, no matter what experiences we have in this life or a next life

You might think that once you survived death, you could be certain that you will live forever. For example, imagine if something like a near-death experience happens to you. After a tractor trailer flattens the car you were driving in, you find your soul drifting above your body, and you travel through a tunnel. You then find yourself in some radiant realm where you see relatives you know are dead. Would you not then be justified in believing with certainty that you are going to live forever?

No. You would then presumably be justified in concluding that you are going to survive much longer. But you still would not know whether the afterlife you had started would last for a finite length of time or an eternal length of time. Your soul, newly liberated from human flesh, might fizzle out after a million or a billion years. You could not be certain that you were going to live forever.

You might think that you could gain certainty of eternal life if you encountered some powerful godlike Higher Being who assured you that you were going to live forever. But there is a reason why you could not be certain about living forever, even in such a case. It would be entirely possible that in the eons of time ahead you might do some terrible thing or commit some bad sin that might make you unworthy of eternal life. In that case you might be spurned by some Higher Power, and your post-mortal existence might end up being only finite in length. Presumably no free moral agent can ever be certain that he will perform morally throughout eternity.

We can never be certain that we will not have an afterlife

Looking at one of the more extreme depictions of life after death advanced by conventional religion (such as the type of depictions imagined by the American preacher Jonathan Edwards), an astute moral critic might say that he is certain that such a scenario will never occur. But no one can ever be certain that he will not experience any type of life after death. It is always possible that some reasonable and fair type of afterlife does occur. As there is no way to experience a non-experience, there is no experience or knowledge you could acquire that would justify certainty about the non-existence of life after death.

We can never be absolutely certain that the universe is older than any one of us

This is a startling assertion, but it is easy to justify it. Let us consider the fact that an omnipotent God could create any type of universe that he wants, including universes other than universes which have that “just created” appearance. An omnipotent God could instantly create from nothing a universe exactly like the universe that existed in 1000 BC or 100 AD or 1000 AD or January 1, 2000. Consider if God wanted to create a universe exactly like the one that existed on midnight Eastern Standard Time at January 1, 2000. God would merely need to will into existence an expanding universe of billions of galaxies, a universe that would include at least one planet with billions of people. God could instantly will into existence those people existing at that date, having them suddenly come into existence with various memories and various states of motion (some walking, some driving, some sleeping, some celebrating the new year in Times Square). Under such a scenario, billions of people would suddenly come into existence, convinced they had lived for years. But they would actually just be recently created.

My point is that we cannot be certain that such a thing did not happen any length of time ago-- one hour ago, one day ago, one year ago, or one decade ago. Or perhaps one century ago or five hundred years ago. The fact that you may have memories of having lived for 20 years does not make it certain that you actually have lived for twenty years. You and everything else in the universe could have been created ten years ago.

About the only argument I can think of against such a possibility is the argument that if God were to instantly create a universe that included people with various ages and memories of the past, it would be rather like a deception (causing people to think they had existed for years when they had really been just recently created); and presumably God would not deceive us in that way. But I'm not sure this argument is very strong. According to conventional theology, earthly life gives us the impression that we are mortal beings with short lifespans, but we are really immortal souls. If a deity could create a universe in which there is such a mismatch between appearance and reality, he might also create a universe in which our memories of how old we are does not match the reality of how old we are.

I am not seriously suggesting that there is even a 1% possibility that the universe was only very recently created. I merely submit that we cannot be absolutely certain that the universe was not very recently created. My own guess about the age of the universe corresponds to the 13.8 billion year age postulated by modern science.