How to Create a Mind: The Secret of Human Thought Revealed

by Ray Kurzweil

René Descartes. His famous “I think, therefore I am” is generally interpreted to extol rational thought, in the sense that “I think, that is I can perform logical thought, therefore I am worthwhile.” Descartes is therefore considered the architect of the Western rational perspective.

This is how I resolve the Western-Eastern divide on consciousness and the physical world. In my view, both perspectives have to be true. On the one hand, it is foolish to deny the physical world. Even if we do live in a simulation, as speculated by Swedish philosopher Nick Bostrom, reality is nonetheless a conceptual level that is real for us. If we accept the existence of the physical world and the evolution that has taken place in it, then we can see that conscious entities have evolved from it. On the other hand, the Eastern perspective—that consciousness is fundamental and represents the only reality that is truly important—is also difficult to deny. Just consider the precious regard we give to conscious persons versus unconscious things. We consider the latter to have no intrinsic value except to the extent that they can influence the subjective experience of conscious persons. Even if we regard consciousness as an emergent property of a complex system, we cannot take the position that it is just another attribute (along with “digestion” and “lactation,” to quote John Searle). It represents what is truly important.

People often feel threatened by discussions that imply the possibility that a machine could be conscious, as they view considerations along these lines as a denigration of the spiritual value of conscious persons. But this reaction reflects a misunderstanding of the concept of a machine.

contemporary examples of technology are not yet worthy of our respect as conscious beings. My prediction is that they will become indistinguishable from biological humans, whom we do regard as conscious beings, and will therefore share in the spiritual value we ascribe to consciousness.

Humans already constitute spiritual machines. Moreover, we will merge with the tools we are creating so closely that the distinction between human and machine will blur until the difference disappears. That process is already well under way, even if most of the machines that extend us are not yet inside our bodies and brains.

“free will” is our apparent ability to choose and act upon whichever of those seem most useful or appropriate, and our insistence upon the idea that such choices are our own.

showed a split-brain patient a picture of a chicken claw to the right visual field (which was seen by his left hemisphere) and a snowy scene to the left visual field (which was seen by his right hemisphere). He then showed a collection of pictures so that both hemispheres could see them. He asked the patient to choose one of the pictures that went well with the first picture. The patient’s left hand (controlled by his right hemisphere) pointed to a picture of a shovel, whereas his right hand pointed to a picture of a chicken. So far so good—the two hemispheres were acting independently and sensibly. “Why did you choose that?” Gazzaniga asked the patient, who answered verbally (controlled by his left-hemisphere speech center), “The chicken claw obviously goes with the chicken.” But then the patient looked down and, noticing his left hand pointing to the shovel, immediately explained this (again with his left-hemisphere-controlled speech center) as “and you need a shovel to clean out the chicken shed.” This is a confabulation. The right hemisphere (which controls the left arm and hand) correctly points to the shovel, but because the left hemisphere (which controls the verbal answer) is unaware of the snow, it confabulates an explanation, yet is not aware that it is confabulating. It is taking responsibility for an action it had never decided on and never took, but thinks that it did. This implies that each of the two hemispheres in a split-brain patient has its own conscious...

Gazzaniga’s tests are not thought experiments but actual mind experiments. While they offer an interesting perspective on the issue of consciousness, they speak even more directly to the issue of free will. In each of these cases, one of the hemispheres believes that it has made a decision that it in fact never made. To what extent is that true for the decisions we make every day?

We are apparently very eager to explain and rationalize our actions, even when we didn’t actually make the decisions that led to them. So just how responsible are we for our decisions?

The Merriam-Webster dictionary defines it as the “freedom of humans to make choices that are not determined by prior causes or by divine intervention.”

“the ability of agents to make choices free from certain kinds of constraints…. The constraint of dominant concern has been…determinism.” Again, it uses the circular word “free” in defining free will, but it does articulate what has been regarded as the principal enemy of free will: determinism.

So what do we mean by determinism? If I put “2 + 2” into a calculator and it displays “4,” can I say that the calculator displayed its free will by deciding to display that “4”? No one would accept that as a demonstration of free will, because the “decision” was predetermined by the internal mechanisms of the calculator and the input.

How about Watson when it answers a Jeopardy! query?

its output is determined by (1) all of its programs at the moment that the query is posed, (2) the query itself, (3) the state of its internal parameters that influence its decisions, and (4) its trillions of bytes of knowledge bases, including encyclopedias. Based on these four categories of information, its output is determined.

So how exactly does a human differ from Watson, such that we ascribe free will to the human but not to the computer program?

The concept of free will—and responsibility, which is a closely aligned idea—is useful, and indeed vital, to maintaining social order, whether or not free will actually exists.

If the universe is a giant cellular automaton, as Dr. Wolfram postulates, there would be no computer big enough—since every computer would be a subset of the universe—that could run such a simulation. Therefore the future state of the universe is completely unknowable even though it is deterministic. Thus even though our decisions are determined (because our bodies and brains are part of a deterministic universe), they are nonetheless inherently unpredictable because we live in (and are part of) a class IV automaton. We cannot predict the future of a class IV automaton except to let the future unfold. For Dr. Wolfram, this is sufficient to allow for free will. We don’t have to look to the universe to see future events that are determined yet unpredictable. None of the scientists who have worked on Watson can predict what it will do, because the program is just too complex and varied, and its performance is based on knowledge that is far too extensive for any human to master. If we believe that humans exhibit free will, then it follows that we have to allow that future versions of Watson or Watson-like machines can exhibit it also.

Although I share Descartes’ confidence that I am conscious, I’m not so sure about free will. It is difficult to escape Schopenhauer’s conclusion that “you can do what you will, but in any given moment of your life you can will only one definite thing and absolutely nothing other than that one thing.” 20 Nonetheless I will continue to act as if I have free will and to believe in it, so long as I don’t have to explain why.

The issue of identity is perhaps even harder to define than consciousness or free will, but is arguably more important.

In the 2030s, when intelligent computerized devices will be the size of blood cells (and keep in mind that white blood cells are sufficiently intelligent to recognize and combat pathogens), we will introduce them noninvasively, no surgery required. Returning to our future scenario, you have the procedure, and as promised, it works just fine—certain of your capabilities have improved. (You have better memory, perhaps.) So are you still you? Your friends certainly think so. You think so. There is no good argument that you’re suddenly a different person. Obviously, you underwent the procedure in order to effect a change in something, but you are still the same you. Your identity hasn’t changed.

You keep opting for additional procedures, your confidence in the process only increasing, until eventually you’ve changed every part of your brain. Each time the procedure was carefully done to preserve all of your neocortical patterns and connections so that you have not lost any of your personality, skills, or memories. There was never a you and a You 2; there was only you. No one, including you, ever notices you ceasing to exist. Indeed—there you are.

The half-life of a neuron microtubule is about ten minutes; the actin filaments in the dendrites last about forty seconds; the proteins that provide energy to the synapses are replaced every hour; the NMDA receptors in synapses are relatively long-lived at five days. So you are completely replaced in a matter of months, which is comparable to the gradual replacement scenario I describe above. Are you the same person you were a few months ago? Certainly there are some differences. Perhaps you learned a few things. But you assume that your identity persists, that you are not continually destroyed and re-created.

We are a pattern that changes slowly but has stability and continuity, even though the stuff constituting the pattern changes quickly. The gradual introduction of nonbiological systems into our bodies and brains will be just another example of the continual turnover of parts that compose us. It will not alter the continuity of our identity any more than the natural replacement of our biological cells does.

a capability that nonbiological systems have that biological systems do not: the ability to be copied, backed up, and re-created. We do that routinely with our devices.

It is an advantage, not a limitation, which is one reason why we are so eager today to continue uploading our memories to the cloud.

It is not true that You 2 is not you—it is you. It is just that there are now two of you.

What I believe will actually happen is that we will continue on the path of the gradual replacement and augmentation scenario until ultimately most of our thinking will be in the cloud.

My core thesis, which I call the law of accelerating returns (LOAR), is that fundamental measures of information technology follow predictable and exponential trajectories,

are there fundamental limits to our ability to compute and transmit information, regardless of paradigm? The answer is yes, based on our current understanding of the physics of computation. Those limits, however, are not very limiting. Ultimately we can expand our intelligence trillions-fold based on molecular computing. By my calculations, we will reach these limits late in this century.

A primary purpose of understanding the brain is to expand our toolkit of techniques to create intelligent systems. Although many AI researchers may not fully appreciate this, they have already been deeply influenced by our knowledge of the principles of the operation of the brain. Understanding the brain also helps us to reverse brain dysfunctions of various kinds. There is, of course, another key goal of the project to reverse-engineer the brain: understanding who we are.

Combining human-level pattern recognition with the inherent speed and accuracy of computers will result in very powerful abilities. But this is not an alien invasion of intelligent machines from Mars—we are creating these tools to make ourselves smarter. I believe that most observers will agree with me that this is what is unique about the human species: We build these tools to extend our own reach.