Philosophy, recent

The Unconstrained Vision of David Deutsch

In his book A Conflict of Visions, Thomas Sowell argues that a good deal of political disagreements can be traced back to different assumptions about human nature. It is not a coincidence if many people seem to systematically fall on the same side of different, apparently unrelated political issues: starting from different visions of human nature and how the world works, people seem to cluster around the same stable sets of political positions (with the help, I would surmise, of some good old tribalism).

Sowell distinguishes between the unconstrained vision and the constrained vision. In the unconstrained vision, human beings are capable of great feats of wisdom, virtue, and intellectual power. Our egoism, our self-interestedness, and our wickedness are not part of our nature, but are instead artifacts of cruel, unfair, or irrational institutions. Given our capacity for enlightenment, it follows that some of us, who find themselves further on the path of perfectibility, can use their intellectual and moral power to elucidate what must be done and get rid of the shackles of the past. This is the vision of Rousseau, Condorcet, and Godwin.

In the constrained vision, however, human nature is deeply, fatally flawed. The moral and intellectual limitations of human beings must be put in check by traditions and institutions that stood the test of time. Since no one can wield the knowledge or moral perfection necessary to guide the whole of society, we need systemic processes to coordinate our self-interested strivings, leading to the emergence of a beneficial social order. This is the vision of Hobbes, Burke, and Smith (and, of course, Sowell himself).

That dichotomy is of course a crude simplification. It is in fact a spectrum, as Sowell himself admits, since no vision is fully constrained or unconstrained. However imperfect, Sowell’s categorization is a valuable instrument of interpretation. He does a great job of showing that many famous philosophers fall squarely within one cluster of visions. And then there are oddballs like David Deutsch.

David Deutsch, a renowned quantum physicist, sometimes hailed as the father of quantum computation, is one of the most original thinkers I’ve ever come across. If you don’t know what I mean, pick up one of his books. In his 1997 The Fabric of Reality, Deutsch presents his “theory of everything” by weaving together what he considers to be the deepest strands of our knowledge: evolution, computation, quantum physics, and epistemology. The resulting tapestry is not only consistent, it is breathtakingly beautiful. And if you think that sounds ambitious, just wait until you read his second book, The Beginning of Infinity.

Nothing can prepare you for a book like that. Deutsch’s argument is straightforward: our potential to make progress is infinite. It could in principle go on forever. The implications of such an optimistic view can only be grasped on the cosmic scale.

The starting point of Deutsch’s reasoning is epistemology—that is, the philosophy of knowledge. David Deutsch is a proponent of Karl Popper’s critical rationalism, according to which knowledge consists of unsupported guesses, and grows through a process of conjectures and refutations. Building on that, Deutsch calls himself a fallibilist. As he explains in his interview with Nautilus (a wonderful introduction to his ideas), fallibilism is the philosophical position that all human endeavours — attempts to create knowledge or achieve anything — are subject to error. There can be no foundation upon which to build “reliable”, “probable” or even “justified” knowledge. The logic of this is very simple: any foundation, any “reason to believe” you got things right needs to be itself justified. Therefore, all attempts to ground knowledge in any form of justification leads to an infinite regress.

However bleak this might seem at first, Deutsch maintains that fallibilism is an optimistic doctrine. The very idea that we are subject to error implies that there is such a thing as being right. The fact that knowledge can’t be justified doesn’t imply that it can’t capture some truth: there’s no need for us to know, or to believe, that something is true in order for it to be true. Following Popper, Deutsch argues that, even though certainty is forever out of reach, through repeated cycles of conjectures and refutations, human knowledge can grow indefinitely.

And the power of knowledge is limitless. Deutsch insists that any physical transformation that is not forbidden by the laws of physics is achievable, given the right knowledge. This idea runs very deep. Deutsch even proposed a new way of formulating the laws of physics, not in terms of initial conditions and laws of motions, but in terms of what transformations are possible — and the distinction between what’s possible or not depends on knowledge. In this worldview, knowledge is not a fringe phenomenon in physics: it is one of its central objects, of immense, cosmical importance. (I’m paraphrasing; this stuff is way too advanced for me). 

Optimism, for Deutsch, amounts to a deep philosophical principle. Either something is impossible, or it is achievable with knowledge. Another way to put it is this: All evils are due to insufficient knowledge.

The Unconstrained

There are a few things about David Deutsch that made me think of Sowell’s A Conflict of Visions. I caught myself wondering where such a mind-blowing vision would fall on the spectrum from constrained to unconstrained. At first, Deutsch’s boundless optimism seemed to evoke the unconstrained view.

Deutsch is highly skeptical of behavioural economics. Its focus on cognitive bias and various other forms of human limitations underplays our power to correct our mistakes: according to him, the very concept of bias is a misconception. He is also critical of evolutionary psychology and behavioural genetics: in a memorable run-in with Geoffrey Miller, he wrote that “explaining differences in human behaviour via genes quickly runs counter to human universality,” that is, the all-encompassing role of knowledge in the fate of human beings. He went as far as to say that “the idea that there is a human condition or a human nature is the epitome of the wrong way of explaining humans.”

This skepticism towards any insistence on human beings’ inadequacies, in light of our capacity to create knowledge, bears the hallmark of the unconstrained view. Moreover, Deutsch cites William Godwin, an eighteenth century English philosopher, as one of his main influences. In A Conflict of Visions, Sowell presents Godwin’s book Enquiry Concerning Political Justice as perhaps the purest example of the unconstrained vision. Godwin, a precursor of anarchism, believed in the power of human virtue and reason to supersede the need for coercive institutions. In Godwin’s vision, human beings’ limitations are not a feature of our nature, but a product of our circumstances. According to Deutsch, Godwin anticipated Popper in many ways, even though he “completely misunderstood economics.”

Another striking example is Deutsch’s rejection of Jared Diamond’s ideas about the role of geography and the environment in the rise of civilization. According to Diamond, a conjunction of environmental factors, such as the presence of vegetal and animal species suitable for domestication and the geographical and climatic characteristics of Eurasia, allowed European societies to make rapid progress. They accumulated cultural innovations, acquired immunities to various germs and developed the technologies they needed to conquer and colonize the rest of the world. Incidentally, Sowell wrote very similar things in his Culture trilogy.

Deutsch will have none of that. As he put it in his 2007 TedTalk, the problem is never resources, that are always plentiful, but knowledge, which is scarce. A culture can only exploit the resources present in its environment if it develops the knowledge required to use them. If a meteorite containing a metal with wonderful properties had fallen in Africa in prehistory, our primitive ancestors would not have known how to use it; if they had the right culture to do so, they wouldn’t need it to make rapid progress.

There’s clearly something unconstrained, almost ethereal, about this irrelevance of parochial factors. According to Deutsch, the beginning of infinity could have taken place anywhere: as he put it, “History is the history of ideas, not of the mechanical effects of biogeography.” And yet, it is striking to notice how much Deutsch’s epistemology owes to the constrained view.

The Constrained

According to Sowell, one of the main differences between the constrained and the unconstrained visions is epistemological in nature. The two visions have different assumptions about what knowledge is, how it can be used, and how scarce it is.

In the unconstrained vision, knowledge consists mainly of articulated propositions that can be understood by an individual. Those who have an unconstrained view of human nature believe in the power of articulated rationality: human reason is capable of elucidating anything, and that which cannot be justified before the tribunal of reason must be discarded. The fact that a tradition stood the test of time is no excuse; in fact, it is suspect, because it must then incorporate the prejudices and ignorance of the past.

In the constrained vision, knowledge is mainly experience, and the scope of knowledge goes far beyond what any particular individual can contemplate at one glance. This particular epistemology owes much to Friedrich Hayek, according to whom knowledge should be understood to…

…include all the human adaptations to environment in which past experience has been incorporated. Not all knowledge in this sense is part of our intellect and our intellect is not the whole of our knowledge. Our habits and skills, our emotional attitudes, our tools and our institutions — all are in this sense more or less effective adaptations formed by past experience, that have grown up by selective elimination of less suitable conduct and which are as much an indispensable foundation of successful action as is our conscious knowledge.

This view of knowledge closely tracks what Popper had in mind when he talked about objective knowledge. (The intellectual affinities between Popper and Hayek are well-known: Conjectures and Refutations is dedicated to Hayek.) For Popper, knowledge does not have to have a knowing subject. It exists in books, brains, computers, but also social organizations, traditions, and our genome: it is, in effect, information, instantiated in various physical substrates, that proved resistant to falsification, in a way reminiscent of Darwinian evolution.

In his magnum opus Knowledge and Decisions, building on Hayek’s seminal 1945 paper, Thomas Sowell insists on another aspect. Knowledge is scarce, and scattered thinly throughout society. What any given individual can know pales in comparison to the sum of knowledge spread out, in a myriad parcels, in a complex civilization. The central concern of economics, therefore, is not a problem of accumulating knowledge in a central authority that could then organize the whole of society and allocate resources for the greater good: given the intellectual limitations of man, such a task is impossible. The problem is communication and coordination. Individual specks of knowledge must be brought to bear on decision-making in the form of incentives through various systemic and institutional mechanisms.

Not only is the scarcity of knowledge central in Deutsch’s epistemology, but it goes with a somewhat tragic view of the human condition. In his appearance on Sam Harris’ podcast, David Deutsch outlined a view of history that seems to come straight out of Thomas Hobbes’s Leviathan:

I see human history as a long period of complete failure — failure, that is, to make any progress. Now, our species has existed for maybe 50,000 years, maybe 100,000 to 200,000 years. The vast majority of that time, people were alive, they were thinking, they were suffering, they wanted things. But nothing ever improved. The improvements that did happen happened so slowly that geologists can’t distinguish the difference between artifacts from one era to another with a resolution of 10,000 years. So from the point of view of a human lifetime, nothing ever improved, with generation upon generation upon generation of suffering and stasis.

It doesn’t get much more constrained than that. Deutsch has some strong-worded criticism for the prevailing view knowledge and progress among most liberal intellectuals:

Although the institutions of our culture are so amazingly good that they have been able to manage stability in the face of rapid change for hundreds of years, the knowledge of what it takes to keep civilization stable in the face of rapidly increasing knowledge is not very widespread. In fact, severe misconceptions about several aspects of it are common among political leaders, educated people, and society at large. We’re like people on a huge, well-designed submarine, which has all sorts of lifesaving devices built in, who don’t know they’re in a submarine. They think they’re in a motorboat, and they’re going to open all the hatches because they want to have a nicer view.

The submarine analogy echoes the distinction between the constrained and the unconstrained visions. It definitely sounds like something Sowell could say. In his defense of the constrained vision, in books like The Vision of the Anointed and Intellectuals and Society, Sowell rants on and on about the tendency of many intellectuals to “anoint” themselves with a special role to help society. The anointed believe themselves to be capable of wielding enough knowledge to judge and prescribe social outcomes, instead of social processes, without being accountable for the results of their ideas. Intellectuals have a dangerous tendency, and powerful incentives, to isolate themselves from any form of feedback and reality-check.

This fits Popperian thinking like a glove. In The Beginning of Infinity, David Deutsch is even more blunt. According to Deutsch, since there is no secure foundation upon which to build knowledge, and since error is the normal state of our knowledge, the only thing we can cling on to is the hope to correct our errors. It therefore follows that the ultimate immoral thing is to destroy the means of correcting errors, that is, to isolate ourselves from criticism. In an imagined dialog between Socrates and the god of knowledge Hermes, David Deutsch puts the following line in the mouth of the philosopher: “Could it be that the moral imperative not to destroy the means of correcting mistakes is the only moral imperative? That all other moral truths follow from it?”

This question is met with an equivocal silence from the god.

The Human Condition, From Constrained to Unconstrained

In light of Sowell’s A Conflict of Visions, David Deutsch appears as a remarkable, unclassifiable thinker. His synthesis of the constrained and unconstrained visions is perhaps the most remarkable thing about his work.

From a constrained view of human history, and fully aware of our mediocre beginnings as primitive beasts, Deutsch believes that the capacity to create knowledge, and the cultural institutions and traditions that allow us to do so, makes us on a par with the gods. Even though we are frail and fallible earthly creatures, made of mundane matter, and even though we come from an excruciating history of stasis, suffering, and stupidity, our knowledge sets us apart in the universe. Ultimately, human knowledge may come to shape the cosmos; through knowledge, we are unconstrained.


Clovis Roussy is a Quebec lawyer. He works as a law clerk at the Court of Appeal of Quebec. His fields of interest are epistemology and moral philosophy. You can follow him on Twitter @cloroussy