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The Edge of Reason: A Rational Skeptic in an Irrational World

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Julian Baggini is a British philosopher who knows how to write for a general audience. Yale University Press has just released his latest book, The Edge of Reason: A Rational Skeptic in an Irrational World. Although about half of the book deals with morality and political philosophy, I’m going to focus here on a couple of salient epistemological points. I trust readers will see their relevance to the effort to develop rational views of largely irrational financial markets.

Baggini sets forth a notion of reason “which is thin enough for there to be mutually comprehensible reasoning between individuals and cultures in a shared discursive space, without it being so thin as to enable anything to count as reasoning, from nuanced step-by-step argument to thumping the table and insisting on the correctness of your position.” His ‘thin’ view “sees rational argument not as a formal, mechanistic, rigid method but simply as the process of giving and assessing objective reasons for belief. These reasons are those which are assessable and comprehensible by any competent thinker, which stand or fall irrespective of our personal values, and are compelling yet open to revision if the evidence changes.”

Reason, Baggini argues, requires judgment. It is “not a pure algorithm that can be set up and left to run by itself to produce true conclusions.” It cannot be completely schematized and formalized. The inescapability of judgment in reasoning is “philosophy’s dirty secret.”

Moreover, frequently philosophy doesn’t rely on arguments at all; instead, it calls on us to attend to and then interpret an observation. “Attending is often more useful than argument. As Wittgenstein put it, the best way to respond to a skeptic who says ‘I don’t know if there is a hand here’ is to say ‘look closer.’ Attending is a crucial element in good reasoning and provides the clearest example of the ways in which philosophising inevitably requires the use of judgement and cannot rely solely on what logic and evidence dictate.”


But back to arguments. A rational argument is “always in principle defeasible—open to revision or rejection—by public criteria of argument and evidence.” This is not the same as to say that it is always falsifiable in Popper’s sense of the word. Popper’s mistake “was to over-specify something which, if stated in more general terms, should be uncontroversial.” First of all, Popper intended falsifiability to be a criterion for demarcating between science and non-science. “So even if the principle works, it does not allow us to distinguish between the rational and the non-rational, unless we make the further claim that the only form of rational discourse is the scientific one. This is impossible, since such a claim would not be a scientific claim but a philosophical one, and so would be self-refuting.” Second, it’s not clear that all scientific claims are actually falsifiable. For Popper, “falsifiability is possible because theories imply predictions, and we can see if these predictions are borne out or not.” But, as Hilary Putnam argued, “’theories do not imply predictions’ in the straightforward way Popper believed. ‘It is only the conjunction of theory with certain ‘auxiliary statements’ … that, in general, implies a prediction…. This means ‘we cannot regard a false prediction as definitively falsifying a theory’ since there is always some uncertainty of the status of the auxiliary statements and their link with the theory being tested.”

Rationality is being sorely tested in the world today. Baggini’s book won’t, of course, prompt people to shut down vituperative Twitter streams or put an end to radical terrorism. Still, as Baggini writes in his introduction, “The rehabilitation of reason is urgent because it is only through the proper use of reason that we can find our way out of the quagmires in which many big issues of our time have become stuck.”

The Edge of Reason: A Rational Skeptic in an Irrational World


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