What is knowledge? How do good beliefs get made?

Transcription

1 What is knowledge? How do good beliefs get made?

2 We are users of our cognitive systems Our cognitive (belief-producing) systems (e.g. perception, memory and inference) largely run automatically. We find ourselves forming beliefs, effortlessly, just as we find ourselves breathing, walking etc. But we can also exert some control over our belief formation! (Just as we can choose to hold our breath.) We can check whether the beliefs that form naturally are based on data and good reasoning. We can think of ourselves as users of our cognitive hardware.

3 Control freak or laissez faire? Some managers are control freaks, or micromanagers. They don t trust their workers to do anything properly, and so check up on everything. Other managers are hands off, or laissez faire. They trust their workers, to the extent of not really knowing what s going on. As users of our own cognitive hardware, how much should we sit back and let those mechanisms do their job? How much should we oversee and overrule these processes?

4 Justified Belief One of the big questions about knowledge is: What extra ingredient is needed, to turn a true belief into knowledge? Internalists say that justification is the extra ingredient.

5 JTB conditions Internalism is the traditional answer to the question of what makes a true belief into a case of knowledge. On this view, a person knows that A iff: they believe that A A is true their belief that A is justified (These are called the JTB conditions, standing for Justified True Belief.)

6 What is justification? But what is a justified belief? A justified belief is one that the user of the cognitive system has checked, and verified. To have a justified belief, it is not enough to let one s cognitive equipment run on autopilot. The conscious mind must get involved, and do such things as: Examine the available empirical evidence Check what beliefs are logically supported by the evidence Ask if there are other possible explanations of the evidence

7 Epistemic responsibility one s cognitive endeavors are justified only if and to the extent that they are aimed at this goal [truth], which means very roughly that one accepts all and only those beliefs which one has good reason to think are true. To accept a belief in the absence of such a reason... is to neglect the pursuit of truth; such acceptance is, one might say, epistemically irresponsible. My contention here is that the idea of avoiding such irresponsibility, of being epistemically responsible in one s believings, is the core of the notion of epistemic justification. Laurence BonJour, The Structure of Empirical Knowledge, p. 8.

8 Being epistemically responsible means being consciously aware of good arguments, based on reliable evidence, that support the truth of one s beliefs. One cannot simply trust the beliefs that form spontaneously in one s mind, saying: No doubt I have a good basis for believing this. My brain wouldn t have produced the belief otherwise. But what that basis is I can t tell you.

9 Earl Conee (Monist, July, 1988 p. 398) A person has a justified belief only if the person has reflective access to evidence that the belief is true.... Such examples make it reasonable to conclude that there is epistemic justification for a belief only where the person has cognitive access to evidence that supports the truth of the belief. Justifying evidence must be internally available. [My emphasis] (N.B. cognitive access and internally available means that you are consciously aware of the evidence.)

10 Internal access is needed for duties Suppose you take on a new job at the nuclear power plant and I instruct you to press a certain button if the temperature of the reactor core goes above a certain point.

11 You see a dial which is labeled Reactor Core Temperature. You ask me, So what you mean is, I should press this button whenever the indicator on that dial goes above that line? Now suppose I respond, No, that's not what I mean. That dial might not be working properly. I want you to press the button whenever the reactor core is above the danger point, regardless of what that dial says. (From Jim Prior s web site)

12 What about perception? Can beliefs that result from perception be justified? Don t such beliefs just pop into our heads Do most people know anything at all about how perception works? Does the user of a cognitive system have any duties regarding the formation of perceptual beliefs? If a user forms a false perceptual belief are they ever to blame? Should they ever be held responsible?

13 What about memory? In a similar way, beliefs produced by memory seem just to pop into our heads, when we try to access our past experiences. Does the user of a cognitive system have any duties regarding memory beliefs? For example, do memory beliefs require independent verification (e.g. by other people, or video footage) before they can be trusted?

14 Assurance Some perceptions are, we might say, perfectly clear. For example we have perfect eyesight, and we see a dog for several seconds, under good lighting, from a few feet away. In such a case we feel very certain that our perception could not be wrong. Locke called this feeling assurance. Perhaps assurance is a design feature of our cognitive apparatus? The user has a duty to withhold belief when assurance is absent?

15 Assurance and internal access (Even though perception is a subconscious process that we cannot supervise, we can at least check whether assurance is present. Assurance is something we re consciously aware of.) Assurance is often present when we remember something, and also when we form a conclusion by reasoning.

16 Assurance in reasoning Descartes described having the strongest kind of assurance about reasoning rather than perception. For example Descartes claimed that he could clearly and distinctly perceive mathematical facts such as 2+3=5. Descartes also had some assurance from the senses, but thought that he had a duty not to form any perceptual beliefs until he had logical proof that the senses are reliable.

17 Clairvoyance case What if God (or evolution) designs a very few people to be clairvoyants? Are the beliefs so produced justified? What if the people have no objective evidence that they re clairvoyants, beyond the clairvoyant experiences themselves? What if the people concerned have (what appears to be) strong scientific evidence that clairvoyance is impossible? (E.g. many people claiming clairvoyance were tested and exposed as frauds.)

18 Clairvoyance case But what if the clairvoyant has assurance? Their experiences feel very real and certain just as real and solid as vision so that the person finds it almost impossible to doubt them. If clairvoyants need objective verification of their clairvoyant ability (before their clairvoyant beliefs count as knowledge) then do we all require our vision, hearing, etc. to be validated independently?

19 The Problem of Radical Scepticism representational realism involves the veil of perception, i.e. a gap between the world as it appears to us, and as it really is. This opens the door to scepticism (= doubt).

20 Sceptical Scenarios Descartes demon The Matrix Putnam s brain in a vat The world is 5 minutes old Solipsism (there are no other people)

21 Sceptical Scenarios In these scenarios, most of what the people in them believe is false. Yet from the inside, so to speak, everything seems normal and fine. These false perceptions are accompanied with strong feelings of assurance. Therefore assurance is not, in principle, a guarantee of truth. So, to have justified beliefs, and knowledge, we must find proof (or at least good evidence) that the skeptical scenarios are all false. (Can we do this?)

22 Externalism Externalists think that knowledge requires warrant, rather than justification. Warrant is something that we don t have internal access to. There are many theories of what warrant requires, e.g.: 1. The belief that p is caused by the fact that p. 2. The belief is formed by a reliable cognitive process. 3. The cognitive process that formed the belief was working properly.

23 Emma the dog Externalists say that Emma (a dog) has knowledge, even though she never checks or verifies the evidence and reasoning that her beliefs are based on. (Emma has never even considered, much less ruled out, the possibility that she is a brain in a vat.)... it is doubtful whether Emma could have even understood the basic idea of having a reason for a belief, an understanding that seems to be required for her to have had fully explicit access to any reasons at all. Thus it is hard to avoid the conclusion that Emma had no justified beliefs (BonJour) (The same goes for children and unsophisticated adults.)

24 Externalism and Scepticism Externalism doesn t answer the sceptic in the sense of giving us evidence or proof that the sceptical scenarios are false. But, for externalists, the impossibility of answering the sceptic in that way doesn t mean that we have no knowledge. Knowledge, for an externalist, just requires that one s cognitive apparatus is working normally. There is no need to show that it is doing so.