Definitions of Knowledge

• Plato’s answer, that knowledge is justified true belief, stood for thousands of years until a 1963 philosophy paper by philosopher Edmund Gettier challenged this definition.
• Gettier described two scenarios, known as Gettier cases, where an individual has a justified true belief but that is not knowledge.
• There are three kinds of knowledge: Ability: knowledge how - e.g. "I know how to ride a bike".
• Acquaintance: knowledge of - e.g. "I know Fred well".
• Propositional: knowledge that - e.g. "I know that London is the capital of England".
• Sosa’s virtue epistemology could correctly say Henry’s belief “there’s a barn” in fake barn county would not qualify as knowledge – despite being true and formed by a reliable method – because it is not apt.
• Aptness provides a link between truth and the third condition that rules out Gettier-style situations where the belief is only true as a result of luck.
• Infallibilism argues that for a belief to count as knowledge, it must be true and justified in such a way as to make it certain.
• According to Sosa, for something to qualify as knowledge the belief must be true as a direct consequence of the believer exercising their intellectual virtues, it must be apt.
• When discussing the definition of knowledge, we are talking about the definition of propositional knowledge specifically.
• Descartes’ three waves of doubt show that certainty is not a necessary condition of knowledge.
• Virtues enable us to achieve our goals, in the same way a virtuous knife enables you to cut, and intellectual virtues would enable you to reliably form true beliefs.
• Justified True Belief, also known as the tripartite definition of knowledge, is: "Justified true belief is the tripartite definition of knowledge".
• The name of the game in defining 'knowledge' is to provide necessary and sufficient conditions.
• Gettier cases are a devastating problem for the tripartite definition of knowledge.
• Smith's belief that "Either Jones owns a Ford or Brown is in Barcelona" is true because the first condition is true (i.e. that Jones owns a Ford) but it turns out it is true because of the second condition (Brown is in Barcelona).
• Despite being a justified true belief, it is wrong to say that Smith's belief counts as knowledge, because it was just luck that led to him being correct.
• In Gettier case 2, Smith has a justified belief that "Jones owns a Ford" and can form the further justified belief that "Either Jones owns a Ford or Brown is in Barcelona" using the principle of disjunctive introduction.
• Gettier cases describe scenarios where an individual has a justified true belief that is not knowledge.
• Gettier's paper describes two scenarios where an individual has a justified true belief that is not knowledge.
• Despite being a justified true belief, Smith's belief does not count as knowledge because it's just luck that led to him being correct.
• In response to Gettier cases, philosophers have tried to come up with new definitions of knowledge that avoid Gettier cases.
• In Gettier case 1, Smith hears the interviewer say "I'm going to give Jones the job" and sees Jones count 10 coins from his pocket, forming the belief that "the man who will get the job has 10 coins in his pocket".
• The two circles overlap perfectly because 'unmarried man' is a perfect definition of 'bachelor'.
• For example, 'unmarried' and 'man' are both necessary to be a 'bachelor' because if you don't meet both these conditions you're not a bachelor.
• A reliable method is one that produces a high percentage of true beliefs.
• True and belief remain unchanged.
• Reliabilism says James knows that P if: P is true, James believes that P, James’s belief that P is caused by a reliable method.
• Both young children and animals are capable of forming beliefs via reliable processes.
• The no false lemmas definition of knowledge faces a similar problem: the fake barn county situation.
• Reliabilism allows for young children and animals to have knowledge.
• The no false lemmas definition of knowledge avoids saying Gettier cases count as knowledge.
• The no false lemmas definition of knowledge aims to strengthen the justification condition of the tripartite definition.
• Generally, these new definitions seek to refine the justification condition of the tripartite definition.
• Henry’s beliefs in 'fake barn county' are not knowledge, because they are not true – the barns are fake.
• Henry is driving through fake barn county, but he doesn’t know the locals do this.
• The no false lemmas definition says that James has knowledge of P if: P is true, James believes that P, James’s belief is justified, and James did not infer that P from anything false.
• The no false lemmas response says Smith’s belief is not knowledge, which is correct.
• Henry often thinks "there’s a barn" when he looks at the fake barns.
• An act of moral virtue is one where the actor both intends to do good and achieves that goal.