Off-campus access
Using PhilPapers from home?
Click here to configure this browser for off-campus access.
- John Hawthorne & Maria Lasonen-Aarnio (2009). Knowledge and Objective Chance. In Patrick Greenough & Duncan Pritchard (eds.), Williamson on Knowledge. Oxford University Press.We think we have lots of substantial knowledge about the future. But contemporary wisdom has it that indeterminism prevails in such a way that just about any proposition about the future has a non-zero objective chance of being false.2, 3 What should one do about this? One, pessimistic, reaction is scepticism about knowledge of the future. We think this should be something of a last resort, especially since this scepticism is likely to infect alleged knowledge of the present and past. One anti-sceptical strategy is to pin our hopes on determinism, conceding that knowledge of the future is unavailable in an indeterministic world. This is not satisfying either: we would rather not be hostage to empirical fortune in the way that this strategy recommends. A final strategy, one that we shall explore in this paper, is one of reconciliation: knowledge of a proposition is compatible with a subject’s belief having a non-zero objective chance of error.4 Following Williamson, we are interested in tying knowledge to the presence or absence of error in close cases, and so we shall explore the connections between knowledge and objective chance within such a framework. We don’t want to get tangled up here in complications involved in attempting to formulate a necessary and sufficient condition for knowledge in terms of safety. Instead, we will assume the following rough and ready necessary condition: a subject knows P only if she could not easily have falsely believed P.5 Assuming that easiness is to be spelt..
Similar books and articles
The goal of this paper is to sketch and defend a new interpretation or theory of objective chance, one that lets us be sure such chances exist and shows how they can play the roles we traditionally grant them. The subtitle obviously emulates the title of Lewis seminal 1980 paper A Subjectivist s Guide to Objective Chance while indicating an important difference in perspective. The view developed below shares two major tenets with Lewis last (1994) account of objective chance: (1) The Principal Principle tells us most of what we know about objective chance; (2) Objective chances are not primitive modal facts, propensities, or powers, but rather facts entailed by the overall pattern of events and processes in the actual world. But it differs from Lewis’ account in most other respects. Another subtitle I considered was A Humean Guide ... But while the account of chance below is compatible with any stripe of Humeanism (Lewis , Hume s, and others ), it presupposes no general Humean philosophy. Only a skeptical attitude about probability itself is presupposed (as in point (2) above); what we should say about causality, laws, modality and so on is left a separate question. Still, I will label the account to be developed “Humean objective chance”.
[1] You have a crystal ball. Unfortunately, it’s defective. Rather than predicting the future, it gives you the chances of future events. Is it then of any use? It certainly seems so. You may not know for sure whether the stock market will crash next week; but if you know for sure that it has an 80% chance of crashing, then you should be 80% confident that it will—and you should plan accordingly. More generally, given that the chance of a proposition A is x%, your conditional credence in A should be x%. This is a chance-credence principle: a principle relating chance (objective probability) with credence (subjective probability, degree of belief). Let’s call it the Minimal Principle (MP).
In this paper I provide a probabilistic account of factual knowledge,[1] based on the notion of chance.[2] This account has some affinity with my chance account of token causation,[3] but it neither relies on it nor presupposes it. Here I concentrate on the core cases of perceptual knowledge and of knowledge by memory (based on perception). The analysis of knowledge presented below is externalist; but pursuing such an analysis need not detract from the significance of attempts to flesh out justificational analyses knowledge; indeed, I have pursued such an analysis in great detail myself.
No categories
The goal of this paper is to sketch and defend a new interpretation or 'theory' of objective chance, one that lets us be sure such chances exist and shows how they can play the roles we traditionally grant them. The account is 'Humean' in claiming that objective chances supervene on the totality of actual events, but does not imply or presuppose a Humean approach to other metaphysical issues such as laws or causation. Like Lewis (1994) I take the Principal Principle (PP) to be the key to understanding objective chance. After describing the main features of Humean objective chance (HOC), I deduce the validity of PP for Humean chances, and end by exploring the limitations of Humean chance.
Why is our knowledge of the past so much more ‘expansive’ (to pick a suitably vague term) than our knowledge of the future, and what is the best way to capture the difference(s) (i.e., in what sense is knowledge of the past more ‘expansive’)? One could reasonably approach these questions by giving necessary conditions for different kinds of knowledge, and showing how some were satisfied by certain propositions about the past, and not by corresponding propositions about the future. I take it that such is the approach of Chapter 6 of Time and Chance (T&C). Here’s another such a proposal, similar to that of, but significantly different from T&C; my purpose in this section is to highlight the differences, by showing how this account fails.
We begin by asking what fallibilism about knowledge is, distinguishing several conceptions of fallibilism and giving reason to accept what we call strong epistemic fallibilism, the view that one can know that something is the case even if there remains an epistemic chance, for one, that it is not the case. The task of the paper, then, concerns how best to defend this sort of fallibilism from the objection that it is “mad,” that it licenses absurd claims such as “I know that p but there’s a chance that not p ” and “ p but it there’s a chance that not p .” We argue that the best defense of fallibilism against this objection—a “pragmatist” defense—makes the following claims. First, while knowledge that p is compatible with an epistemic chance that not- p , it is compatible only with an insignificant such chance. Second, the insignificance of the chance that not- p is plausibly understood in terms of the irrelevance of that chance to p ’s serving as a ‘justifier’, for action as well as belief. In other words, if you know that p , then any chance for you that not p doesn’t stand in the way of p ’s being properly put to work as a basis for action and belief.
Knowledge in an Uncertain World is an exploration of the relation between knowledge, reasons, and justification. According to the primary argument of the book, you can rely on what you know in action and belief, because what you know can be a reason you have and you can rely on the reasons you have. If knowledge doesn't allow for a chance of error, then this result is unsurprising. But if knowledge does allow for a chance of error--as seems required if we know much of anything at all--this result entails the denial of a received position in epistemology. Because any chance of error, if the stakes are high enough, can make a difference to what can be relied on, two subjects with the same evidence and generally the same strength of epistemic position for a proposition can differ with respect to whether they are in a position to know. In defending these points, Fantl and McGrath investigate the ramifications for debates about epistemological externalism and contextualism, the value and importance of knowledge, Wittgensteinian hinge propositions, Bayesianism, and the nature of belief. The book is essential reading for epistemologists, philosophers who work on reasons and rationality, philosophers of language and mind, and decision theorists.
A theory of objective, single-case chances is presented and defended. The theory states that the chance of an event E is its epistemic probability, given maximal knowledge of the possible causes of E. This theory is uniquely successful in entailing all the known properties of chance, but involves heavy metaphysical commitment. It requires an objective rationality that determines proper degrees of belief in some contexts.
The two main insights of the account that are at the heart of the notion of knowledge are that the belief that p amounts to high token indicativity of the fact that p, and that knowledge endows high level of immunity from error. In this outline we shall deal with perceptual knowledge and perception-based memory. For these modes of knowledge, another condition is required, beyond that of high token indicativity, which secures the appropriate discriminability condition for knowledge. These conditions will be spelled out in terms of objective chance. So the truth conditions of knowledge ascriptions of that sort will be in terms of truth, belief and chance alone.
No categories
1. As John Hawthorne and Maria Lasonen-Aarnio appreciate, some of the central issues raised in their ‘Knowledge and Objective Chance’ arise for all but the most extreme theories of knowledge. In a wide range of cases, according to very plausible everyday judgments, we know something about the future, even though, according to quantum mechanics, our belief has a small but nonzero chance (objective probability) of being untrue. In easily constructed examples, we are in that position simultaneously with respect to many different propositions about the future that are equiprobable and probabilistically independent of each other, at least to a reasonable approximation.
No categories
Discussion of John Hawthorne & Maria Lasonen-Aarnio, Knowledge and Objective Chance
|
|
There are no threads in this forum |
Nothing in this forum yet.

