Péter Hartl & Dr. Tihamér Margitay Dept. of Philosophy and the History of Science 1111 Budapest, Egry J. st. 1. E EPISTEMOLOGY

Hartl & Margitay – Epistemology Fundamental Questions 1. Cognitive states What are our cognitive states? (Knowledge, belief, perceptual state etc.) How are they related? What are their objects? When are they acceptable? 2. Cognitive methods What are our cognitive methods? (Inference, perception, etc.) Are they domain specific or universal? When are they acceptable? Epistemology is essentially normative: it is to deliver standards of evaluation for our cognitive states and methods. Where are the limits of our knowledge? What can be known and what cannot?

Hartl & Margitay – Epistemology What is knowledge (the most precious cognitive state)? Is knowledge possible at all? What are the sources of knowledge and how can they produce knowledge? (What justifies our beliefs?) (Epistemology = theory of knowledge) Epistemology in a Narrower Sense

Hartl & Margitay – Epistemology Psychology: Mainly descriptive: How do we see, come to believe etc.? Impartial: true and false beliefs included Knowledge, truth and falsity etc. are taken for granted Uses the methods of science, and takes it for granted Philosophy Normative: What is knowledge? What are the criteria for correctness, rationality etc.? Interested in truth, veracity etc. Uses the methods of philosophy Reflexive: the philosopher’s and the scientist’s knowledge are also part of the problem Philosophy and Psychology About Knowledge I.

Hartl & Margitay – Epistemology The relationship between epistemology and cognitive psychology: Epistemology is prior to and should serve as a foundation for cog.psy Epistemology and cog.psy complement each other talking about different aspects of knowledge (conceptual and empirical) using different methods etc. Epistemology is just part of cog.psy They are independent talking about different things: the concept of „knowledge” and the way we acquire beliefs, respectively. What knowledge should be and we acquire whatever we call knowledge. Philosophy and Psychology About Knowledge II.

Hartl & Margitay – Epistemology Two important philosophical projects stimulated and contributed to epistemological enquiry especially: Definition of knowledge Skepticism Good points to start our philosophical journey. Examples: Two Philosophical Projects

Hartl & Margitay – Epistemology Knowledge: propositional knowledge (knowing-that), non-propositional knowledge (knowing-how) Knowledge is a special kind of belief-state (Perhaps special kinds of other cognitive states – e.g. special perceptual states -- also constitute knowledge without beliefs: non-propositional knowledge) Knowledge is justified true belief, that is, s knows that p if, and only if s belives that p s is justified in believing that p p is true Justification supplyes reasons for the belief in p. (It is a matter of degree.) This definition captures pretty much of what we require of knowledge. Knowledge and Belief

Hartl & Margitay – Epistemology Gettier’s counter-examples: Smith and Jones have applied for the same job. Smith is justified in believing that (a) Jones will get the job, and that (b) Jones has ten coins in his pocket. On the basis of (a) and (b) Smith infers, and thus is justified in believing, that (c) the person who will get the job has ten coins in his pocket. As it turns out, Smith himself will get the job, and he also happens to have ten coins in his pocket. So, although Smith is justified in believing the true proposition (c), Smith does not know (c). It follows that something more is needed for knowledge than the 3 conditions of the definition above. Gettier’s Problem

Hartl & Margitay – Epistemology 1. Knowledge is impossible: one does not know that p because one cannot know. 2. Justification is impossible because any belief / no belief can be justified. The sceptical arguments

Hartl & Margitay – Epistemology Brain in a vat (BV) and Descrates’ evil demon Neuroscientist and Other Demons

Hartl & Margitay – Epistemology

Hartl & Margitay – Epistemology Ex hypothesis: You don’t know that you are not a BV. P1 You know that you are reading this. P2You know that (if you are reading this then you are not a BV.) C1= P3 Therefore if (you know that you are reading this) then (you know also that you are not a BV). P4 You do not know that you are not a BV. C2 Therefore you do not know that you are reading this. C3Therefore you do not know anything about the world. You can replace „know” with „are justified”, and you will get the skeptical conclusion about justification. The Argument

Hartl & Margitay – Epistemology The argument does not show that we are BV. we no nothing. we must be skeptic our beliefs are false etc. It shows that the premises are inconsistent with that we do know quite a few things (the denial of C3). So some of the premises must be false (or indeed we do not know anything). By analyzing the inconsistency, we can learn from knowledge. The Use of the Skeptical Argument