The first question
us in making a complete rational examination of existence is whether we truly exist at all. We could, after all, be the fleeting imagination
of a higher power
with no real substance. You, the reader (or I, the writer), could be a brain floating in a jar
as part of someone’s experiment
; or either of us could be a computer program
made to think we are an independent being. One of us may be the only thing of our kind which exists. Our eyes and ears, even our sense of touch, may not be trusted, for as “real” as they seem to us, they are only electronic signals being fed into our brain for processing. Signals may be replicated, falsified -- and that’s just presuming that what we believe as to electricity and biochemistry is the truth, and not itself an illusion!! This question has bothered many before, and rightly ought to capture the interest of many now and in the future.
is best known for the pronouncement “Cogito, ergo sum”: “I think, therefore I am”; more fully, his statement was in actuality ‘‘Dubito, ergo cogito, ergo sum’’ (I doubt, therefore I think, therefore I am).
The core of this argument is that each of us has an existence which is at least certain enough to result in our belief that we exist (or at least, you, the reader of these words believe that you exist, even if the rest of us may be illusions). Even if our existence is nothing more than an illusion which is good enough to fool us, at least we have “sufficient” existence to be fooled by it.
This enunciation was actually not the first attempt to forge such a connection. Karen Armstrong
writes that “anticipating Descartes, Augustine
argues that knowledge of ourselves is the bedrock of all other certainty. Even our experience of doubt makes us conscious of ourselves.” Augustine’s formula was “Si …
fallor, sum”; “If I am mistaken, I am.”
A variation of this form was enunciated in the Eleventh Century, by Abū Alī ibn Sīnā, a Muslim scientist and philosopher better known in the Western World as Avicenna
. While imprisoned in a fortress by the emir of Hamadhan, Avicenna penned the thought experiment of the “Floating Man.” Avicenna implored the reader to imagine himself afloat in the air, cut off from all senses, even those of inhabiting his own body. Because such a person would still have self-consciousness, wrote Avicenna, this self-consciousness need not reflect any physical thing; instead, it must be a substance all its own.
And as such, Descartes follows the path to confirmation of the self blazed by Augustine and Avicenna. The particular application of doubt in this formula was actually Descartes’ great innovation -- even if our sole consideration is to doubt our existence, we must have at least enough of an existence to entertain such doubt:
But I have convinced myself that there is absolutely nothing in the world, no sky, no earth, no minds, no bodies. Does it now follow that I too do not exist? No. If I convinced myself of something... then I certainly existed. But there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me. In that case I too undoubtedly exist, if he is deceiving me; and let him deceive me as much as he can, he will never bring it about that I am nothing so long as I think that I am something.
Descartes finds his own existence so confirmed, concluding “after considering everything very thoroughly… the proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind.” Descartes thereupon proceeds to use variations of the Ontological Argument
to posit a benevolent God (though the Ontological Argument can truly relay nothing as to a God’s benevolence). This, he uses as a basis to believe that the world he perceives is not illusory, as such a God would not allow him to be fooled into believing in an illusory world.
The conclusion reached by Descartes is unfortunately undone in the light of modern technology
. In at least two ways, our capabilities in this regard are fast approaching the point where humans will indeed be able to engage in precisely the deceit which Descartes discards as prohibited by God. First, we will at some foreseeable point be able to create computer programs which simulate a mind
, and feed these programs artificial indicia of sensation, perhaps even fooling them into thinking they are persons experiencing the world in the way which we are used to experiencing our world. Second, we will in much the same time frame achieve the ability able to create artificial stimuli which are sufficiently real to fool actual humans.
Naturally, these possibilities have been expounded upon in fiction
. The latter is in actuality the core concept of The Matrix
movie series, in which the protagonist learns that the experiences he and other humans share in the world they believe to be real are in actuality illusions created by a computer, their real bodies being housed in an enormous network of pods. The former has been depicted in various episodes of the later incarnations of the Star Trek television series, in which the “real” characters engage in recreation on “holodecks,” simulated environments complete with computer-generated people who seem self-aware, but may be unaware that they are simulacra. These holodeck people may simply mimic self-awareness without actually experiencing it. But two episodes relate a certain instance of artificial self-awareness. In “Elementary, Dear Data,” crew members spur the creation of a holodeck program including a self-aware simulation of the character of Moriarty
, a recurring villain from the Sherlock Holmes
stories of Sir Arthur Conan Doyle
. This character seizes control of the Enterprise, relenting when it is revealed to him that he is nothing more than a simulation, unable to leave the holodeck. In the later episode, “Ship in a Bottle,” Moriarty attempts to force crew members to find a way to make him “real,” but is instead tricked into entering an alternate simulation -- a self-aware artificial mind, tricked (once again) into believing that it is experiencing a real existence in what is actually an artificial environment.
Fictional accounts aside, it is highly likely that such technology will exist in the relatively near future. When it does, it will inevitably actually be used on some people, either with the intent of deceiving them, or at their request, for purposes of entertainment. It is entirely possible that this technology will enable the user to suppress their “true” memories of the world, providing them with an existence which they subjectively believe to be the entirety of their experience. There is, furthermore, no reason at all why the recipients of these illusions ought to be constrained to experience only the sorts of sensations which accord with our familiar laws of physics. And so, new technology could even lead us to experience sensations which are unjustified by anything which is or could be in the real world.
And such illusions are not confined to a technological future. They exist still today in the phenomenon of schizophrenia. People experiencing insane delusions are divorced from the hard-nosed physical reality which surrounds them, see and hear things which are simply not there as readily as any machinery might induce. As an aside, the understanding of the world expressed by the sanest and most rational amongst us deviates far from an underlying reality of which we ought, in all good conscience, to be aware. For example, the appearance and consequent belief that the world is stationary are illusions. As Heraclitus observed, the world -- and we too -- are in constant flux, always changing though we may have the illusion of homeostasis. This is part of what Arthur Stanley Eddington
was trying to convey in comparing the electrons in the floorboards to a swarm of flies, and yet it is Eddington who seems less rational for pointing out a scientific truth!!
This leads to the question, how may we be sure that anything we perceive is real? Descartes confronted this question, and decided that there must be a God who would not allow us to be deceived, but the basis of this decision is an argument which was itself irrevocably flawed, and is on the verge of being rendered absolutely moot by technology. The unsettling truth is that it is simply not possible to be absolutely certain of anything. Bertrand Russell may have put it best when he declared: “To teach how to live without certainty, and yet without being paralyzed by hesitation, is perhaps the chief thing that philosophy, in our age, can still do for those who study it.” The illusion of some semblance of philosophical certainty is not worth pursuing to the nth degree -- there are more important questions. We may instead only determine whether it is reasonable to believe in the reality of a particular proposition, and what probability
to assign to such proposition.