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• Epistemology is the study of how we know (anything) at all; the nature of truth; the nature of justification; the nature of knowledge; the nature of belief (propositional) states.
• In this course, we have thus far seen that the Ancient Greeks, up till Plato, tended to not distinguish these carefully. *debatable
EPISTEMOLOGY
• In this lecture we will discuss briefly where the debates lie in epistemology, which is why you will see that Plato in the Theaetetus hedges his bets on knowledge being Justified True Belief (JTB henceforth).
EPISTEMOLOGY
• Problems for JTB
• 1. It only covers knowledge-that (propositional knowledge); not knowledge-how (skill). I can know how to ride a bicycle without having a justified belief that I can ride a bicycle, and without knowing that I know, and without any other propositional states about it at all. Indeed, a non-human animal can be trained to ride a bicycle and still be reasonably said to know how to ride a bicycle.
EPISTEMOLOGY
• Problems for JTB
• 2. It doesn’t cover coincidences and necessary causal conditions. Consider a clock. I can look at the time. It says, “12:40”. Suppose, however, it’s an analog clock and it has stopped. But suppose it is in fact 12:40 anyway. I have a justified and true belief that it is 12:40. Do I know that it is 12:40? No. Because it’s a coincidence.
• 3. What is “justification”? We need meaningful causally necessary connections from justification to belief before we have knowledge; coincidences don’t count. Consider accidents of geography and culture.
EPISTEMOLOGY
• Problems for JTB
• We have to have come to know through the “right kind of way” (Mark Leon’s phrase).
• If I am brainwashed by an evil scientist to have a propositional state that it is 12:40 just at the instant that a working clock strikes 12:40, I have a justified true belief that it is 12:40. But I still do not know it is 12:40, because I did not come to that belief in the right kind of way.
EPISTEMOLOGY
• Problems for JTB
• But how do we characterise “right kind of way”? What causal determinants are ruled out and on what grounds? Why is observing information on TV “normal” but neural implants “abnormal”? Consider the century we live in: TV is normal now, but what about 200 years hence? What if quantum mechanics gives me a randomly correct true belief which is justified (as far as I can tell), but I came to the belief because of a quantum fluctuation in my brain?
• If we can’t pin down normal vs abnormal causes, we can’t ever say that we know. Implications for free-will.
EPISTEMOLOGY
• Problems for JTB
• As we can see, JTB isn’t quite the answer. It needs to be something more like “A JTB which was caused in the right kind of way”.
• But again… what is “right” kind of way…? Does it exclude Descartes, nefarious neurosurgeons, Goebbels, etc…? On what basis?
EPISTEMOLOGY
• PNC/LEM
• The principle of non-contradiction: you may not say A & ¬A (i.e. ¬[A & ¬A])
• or Law of Excluded Middle: only A v ¬A
• These two are logically equivalent: ¬[A & ¬A] = [A v ¬A]Boolean proof:¬[ T & F ] = [ T v F ]¬ F = T T = T
EPISTEMOLOGY
• PNC/LEM
• But some logicians allow that there might be more than two truth conditions; there might be as many as four:
• True [1, say]
• False [0, say]
• Indeterminate (quantum wavefunction prior to collapse);think of the Schrödinger’s Cat case [x, say; only has a value on usage]
• Indeterminable (cannot ever be known) [1/0 ; √-1, say]
EPISTEMOLOGY
• PNC/LEM
• From this it follows that there might not be circumstances which have definite true/false statements applicable to them.
• Probability theory only allocates probabilities in the range [0;1] but in practice it’s more like (0;1) or (1/∞ ; 0.999’).
• Probability theory is more popular nowadays in making arguments rather than logical entailment claims.
EPISTEMOLOGY
• Problems for Empiricism
• Ultimately, truth or falsity claims do have to tie to the real world; which is why up till *Plato we find a confusion between epistemic and ontological claims; that things are true because that is how they are in the real world
• However, there are problems with claiming that the empirical is the true…
EPISTEMOLOGY
• Problems for Empiricism
• Descartes/The Matrix/Creatio Continuans: how do we know that what we see is not at the whim of an external force and is not in some sense an illusion?
• Coherentism (that our beliefs are true if they’re coherent/link up consistently/make sense) doesn’t help because we could just be having a coherent illusion (think of a coherent but false scientific theory, or a dream for example)
EPISTEMOLOGY
• Problems for Empiricism
• Correspondence theory of truth: does it correspond to how the world is
• Positivism: science/empiricism + correspondence theory = truth. “ According to this way of thinking, a scientific theory is a mathematical model that describes and codifies the observations we make.” — Hawking.
• Logical positivism: positivism and truth = logic; no metaphysical speculation. Empiricism plus rationalism.
EPISTEMOLOGY
• Problems for Empiricism
• Reductionism (e.g. social theory) and status quo politics.
• That the true is that which refers to the external world begs questions of content externalism and skepticism. Also, a priori truths of some types do not require content externalism/external reference, think of 1+1=2 or “bachelors are unmarried men” ; these are true even in an illusion world. Need to offer a theory to answer this.
• Experientialism/Phenomenology objection — Theaetetus’ initial view.
EPISTEMOLOGY
• Conclusory remarks
• 1. JTB is OK but it lacks nuance for odd scenarios like quantum causation, coincidences, brainwashing
• 2. There may be more than two values of truth (but: is it true that there are more than two values of truth, ad absurdum)
• 3. If “true” means “it exists” or “such it is in reality”, which is what we’re committed to when we say “is” or “are”, we run into the problems with positivism and/or empiricism.
EPISTEMOLOGY
• Conclusory remarks
• 4. So what is knowledge and what is truth?
EPISTEMOLOGY
• Thank you!
EPISTEMOLOGY
