This is not a topic to which I can do justice in a single post, or even, I expect, a series of posts, but let me make this a placeholder and a promise of more to come. I want to register a general and vigorous protest against thought-experiments of the Turing test and Chinese room variety. These two experiments are specific to debates about intelligence (natural or artificial) and consciousness (ditto), but may also be understood as subsets of a much larger category of what we might call veil-of-ignorance strategies. These strategies, in turn, imitate the algebraic simplification of expressions.

The common method here goes something like this: when faced with a tricky philosophical problem, it’s useful to strip away all the irrelevant contextual details so as to isolate the key issues involved, which then, so isolated, will be easier to analyze. The essential problem with this method is its assumption that we know in advance which elements of a complex problem are essential and which are extraneous. But we rarely know that; indeed, we can only know that if we have already made significant progress towards solving our problem. So in “simplifying” our choices by taking an enormous complex of knowledge — the broad range of knowledge that we bring to all of our everyday decisions — and placing almost all of it behind a veil of ignorance, we may well be creating a situation so artificially reductive that it tells us nothing at all about the subjects we’re inquiring into. Moreover, we are likely to be eliminating not just what we explicitly know but also the tacit knowledge whose vital importance to our cognitive experience Michael Polanyi has so eloquently emphasized.

By contrast to the veil-of-ignorance approach, consider its near-opposite, the approach to logic and argumentation developed by Stephen Toulmin in his The Uses of Argument. For Toulmin, the problem with most traditional approaches to logic is this very tendency to simplification I’ve been discussing — a simplification that can produce, paradoxically enough, its own unexpected complications and subtleties. Toulmin says that by the middle of the twentieth century formal philosophical logic had become unfortunately disconnected from what Aristotle had been interested in: “claims and conclusions of a kind that anyone might have occasion to make.” Toulmin comments that “it may be surprising to find how little progress has been made in our understanding of the answers in all the centuries since the birth, with Aristotle, of the science of logic.”

So Toulmin sets out to provide an account of how, in ordinary life as well as in philosophical discourse, arguments are actually made and actually received. Aristotle had in one sense set us off on the wrong foot by seeking to make logic a “formal science — an episteme.” This led in turn, and eventually, to attempts to make logic a matter of purely formal mathematical rigor. But to follow this model is to abstract arguments completely out of the lifeworld in which they take place, and leave us nothing to say about the everyday debates that shape our experience. Toulmin opts instead for a “jurisprudential analogy”: a claim that we evaluate arguments in the same complex, nuanced, and multivalent way that evidence is weighed in law. When we evaluate arguments in this way we don’t get to begin by ruling very much out of bounds: many different kinds of evidence remain in play, and we just have to figure out how we see them in relation to one another. Thus Toulmin re-thinks “the uses of argument” and what counts as responsible evaluation of the arguments that we regularly confront.

It seems to me that when we try to understand intelligence and consciousness we need to imitate Toulmin’s strategy, and that if we don’t we are likely to trivialize and reduce human beings, and the human lifeworld, in pernicious ways. It’s for this reason that I would like to call for an end to simplifying thought experiments. (Not that anyone will listen.)

So: more about all this in future posts, with reflections on Mark Halpern’s 2006 essay on “The Trouble with the Turing Test”.


  1. Lots to consider here, but I’ll be brief (reductive). You wrote that “to follow this model is to abstract arguments completely out of the lifeworld in which they take place,” which is also a good description of modern consciousness, which with its left-brain dominance takes attributes of the scientific method, namely, categorization and abstraction, to their illogical extremes. Iain McGilchrist demonstrates this pretty clearly in his book The Master and His Emissary. The playing field, however, isn’t a few largely irrelevant thought experiments occupying the restless minds of theorists but instead the general public, whose minds are misshaped by unwholesome influences that promote the value of signifiers over actual things and/or experiences.

  2. I truly believe Toulmin is one of the great underappreciated geniuses of the 20th century– and someone who lived a really remarkable life.

  3. Is it appropriate to use Toulmin to call for an end to simplified thought experiments? This, to me, is a surprising conclusion to your more general point about arguments being complicated. It seems to me that a simplification is just one more way of viewing a complicated issue, a way of temporarily attending to a tacit element, acknowledging the possibility of distortion. Couldn't we simply call for the end of making these arguments weightier than they should be?

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