The Justified True Belief Theory of Knowledge Today’s objectives: 1)To be able to explain the Justified True Belief theory of knowledge. 2)To learn the meaning of the terms ‘necessary’ and ‘sufficient’. 3)To begin to analyse whether the tripartite conditions for knowledge are individually necessary.

The Tripartite Definition of Knowledge/ The Justified True Belief Definition of Knowledge. Knowledge as justified, true belief. If someone knows a proposition then three conditions must be satisfied: the person must believe the proposition, it must be true, and it must be justified. S knows that p if and only if: (e.g. Sharon knows that Paris is the capital of France if and only if...) 1)S believes that p (the belief condition; e.g. Sharon believes Paris is the capital of France) 2)p is true (the truth condition; e.g. Paris is indeed the Capital of France) 3)S has adequate or sufficient evidence for p, or is justified in believing p (The evidence condition; e.g. Sharon read that Paris is the capital of France in an encyclopaedia). For Plato, what is the difference between true belief and knowledge?

Necessary and Sufficient Conditions The proposition ‘S knows that p’ is true if and only if S believes that p, p is true and S has adequate justification for her belief. These three conditions are said to be individually necessary AND jointly sufficient for saying that ‘S knows that p’. Necessary = you need each condition to have knowledge. Sufficient = if you have all three conditions then you definitely have knowledge. Lacewing Read pp to work out what the terms ‘necessary’ and ‘sufficient’ mean.  A necessary condition for some state of affairs X is a condition that must be satisfied in order for X to obtain. e.g. A necessary condition for John to be a bachelor is that he is male.  A sufficient condition for some state of affairs X is a condition that, if satisfied, guarantees that S obtains. e.g. The sufficient conditions for John to be a bachelor are that he is male, that he is unmarried and that he is an adult.

Outline the tripartite definition of knowledge (5 marks) AQA: The examiner is looking for: -‘A full, clear and precise explanation’. - ‘The student makes logical links between precisely identified points, with no redundancy’. Redundancy = unnecessary/irrelevant detail. Make sure you include the terminology necessary and sufficient. 5 marks – A full, clear and precise explanation. – The student makes logical links between precisely identified points, with no redundancy. 4 marks – A clear explanation, with logical links, but some imprecision/redundancy. 3 marks – The substantive content of the explanation is present and there is an attempt at logical thinking, but the explanation is not full and/or precise. 2 marks – One or two relevant points made, but not precisely. The logic is unclear. 1 mark – Fragmented points with no logical structure. 0 marks – Nothing written worthy of credit.

1) Read the scenarios in pairs and check to see whether: (a)The person believes the fact (the belief condition) (b)The fact is true (the truth condition) (c)The person would be justified in believing it (the evidence condition). 2) Did using the three conditions match your own intuitions in each of the cases? (i) Davina thinks that monkeys are more intelligent than humans because her mate told her so. (ii) Ravi reckons the sun will set at 19:02 on Sunday having read as much in the paper. And it does. (iii) The forecast says there is a chance of rain tomorrow. Looking at the sky, farmer Pete is convinced it will be dry. It stays dry the whole day. (iv) Having been told by his parents and having read books and watched videos on the subject, young Victor is convinced that Santa Claus exists. (v) Hamid is convinced that earth is the 3 rd planet from the sun because Mickey Mouse told him so in a dream. (vi) Tamsin learns from a texbook that Hamlet is Shakespeare’s longest play (which it is). (vii) Will watches five videos of Shakespeare plays and concludes by their length that Hamlet must be Shakespeare’s longest play. (viii) Colin is going out with Simone. However at a party he kisses Fiona. No one sees a thing. Back at college Nigel is secretly in love with Simone. To try to get them to split up he makes up a rumour, telling Brian that Colin and Fiona got off at the party. Later Charlie hears this rumour and believes it. We are now going to assess whether each of the conditions for knowledge (according to the tripartite view) are individually necessary...

Are the JTB conditions individually necessary? In small groups, read the information in the blue book (pp ) and answer the questions on the sheet, in order to assess whether the conditions are necessary for knowledge. It is up to you which one you start with – discuss the answers as you work through.

Homework (due next lesson) 1)Finish completing the questions in order to analyse whether they are necessary for knowledge. 2)Outline the argument that the belief condition is not necessary for knowledge. (9 marks) AQA Examiner looking for: o The answer is set out in a clear, integrated and logical form. The content of the answer is correct. The material is clearly relevant and points are made clearly and precisely. o There may be some redundancy or lack of clarity in particular points, but not sufficient to detract from the answer. o Technical philosophical language is used appropriately and consistently.

Today’s objectives: 1)To be able to explain the Justified True Belief theory of knowledge. 2)To learn the meaning of the terms ‘necessary’ and ‘sufficient’. 3)To begin to analyse whether the tripartite conditions for knowledge are individually necessary. Fill in the blanks with either ‘necessary’, ‘sufficient’ or ‘necessary and sufficient’: 1)Having four sides is _________ for being a square. 2)Being a square is __________ for having four sides. 3)Having three straight sides is ___________ for being a triangle. Do you think that the justification condition is necessary for knowledge? necessary sufficient Necessary and sufficient

How confident do you feel with analysing the conditions of knowledge for their necessity? Not at all confident Very confident