How should propositional knowledge be defined? ---------------------------------------------- ### Introduction - Propositional knwowledge is factual knowledge about the external world - In this essay I will judge three different theories of knowledge and how well they perform as definitions of knowledge 1. Tripartite view of knowledge 2. Infallibilism 3. Reliablilism ### Para 1: Tripartite view of knowledge - Defines knowledge as justified true belief (K = J + T + B) - Three components are all neccessary and together are jointly sufficient for a proposition to be regarded as knowledge - Positive of K = J + T + B is that it is a simple definition of knowledge that makes it easy to apply in everyday scenarios - Allows for cases where a proposition that fulfils the criteria of being J+T+B is is correct due to luck. For example gettier cases ( Explain Smith and Jones) - Smith arrives at Justified True belief through a false intermediary belief which makes his proposition being correct nothing more than luck - This is a problem as it shows that J, T and B are not jointly sufficient for a proposition to be regarded as knowledge ### Para 2: No false lemmas condition - Changes K = J + T + B to K = J + T + B + N where N is the 'no false lemmas' condition - N condition means that the justification for belief in a propostion cannot stem from a false intermediary belief - So with the new definition of knowledge Smith does not have knowledge as Smith arrives at J + T + B via the false intermediary belief that Jones would get the job - However, K = J + T + B + N fails to account for 'fake barn cases' (Explain fake barn cases) - In fake barn cases, most would say that person does not have knowledge, as he arrives at the true belief through luck. He does not have any false intermediary beliefs and has justification for believing that the barn is real - So K = J + T + B + N is not an adequate definition of knowledge (all 4 components are not jointly sufficient) ### Para 3: Infallibilism - Infallibilists argue that a proposition cannot only be counted as knowledge if its justification is so strong that that it cannot be rationally doubted. This makes knowledge infallible. - Infallibilists assert that as belief is wavering and infallible, any proposition which is believed could be cast into doubt. This makes it incompatible with knowledge - This definition of knowledge is certainly sufficient definition of knowledge. The accuracy and justification of all the propositions that fulfil the infalliblist conditions are beyond rational doubt. - However it is too restrictive and may exclude propostions that the general public regard as knowledge. - It may also lead to scepticism and solipsism as it places all items that we generally regard as knowledge under doubt, making it a poor working definition of knowledge that is not really applicable to everyday life ### Para 4: Reliablism - Reliabilism defines knowledge as K = R + T + B (Knowledge is true belief obtained through a reliable process) - A reliable process is any method which results in a high ratio of true beliefs - Passes Gettier Cases - Fails fake barn case, so not jointly sufficient definition - Robert Nozick adds 'sensitivity condition' : 'if p were false, s would no longer believe in p'. This means it passes fake barn cases so K = R + T + B + S - This is more successful than the other definitions because it (a) is a sufficient definition for human knowledge (b) it isn't restrictive like infalliblism, and (c) it means that non-verbal entities such as babies and animals can be shown to posess knowledge even when they can't provide justification verbally by looking at their behaviour Conclusion: ----------- - Summarise points