RATIONALISM AND EMPIRICISM: KNOWLEDGE EMPIRICISM Epistemology

Today’s lesson You will learn how to explain knowledge empiricism: the view that all synthetic knowledge is a posteriori and all a priori knowledge is merely analytic

Practice definition questions: What is empiricism? (2 marks) What is rationalism? (2 marks)  Write your own answer  Share your answer with your partner – how could your answer be improved?  Just give a clear, correct answer  Answer the question, then stop  DON’T waffle – don’t write irrelevant information

Textbooks, p What does Hume mean by ‘relations of ideas’ and ‘matters of fact’?

Hume’s Fork – p.50 Hume divided knowledge into “relations of ideas” and “matters of fact” Relations of ideas are analytic truths or a priori knowledge  These are such things as “All bachelors are unmarried”  These are certain because we cannot conceive of them being otherwise Matters of fact, however, can be falsified  I may say, “The sun will rise tomorrow” (which is extremely likely) – but is possible that it will not

Hume’s Fork This shows us that Hume did accept the existence of a priori knowledge; indeed all empiricists accept that logical facts can be known a priori. So no-one is really claiming that all ideas come from sense impressions. However, they would argue that basic facts drawn from analytical propositions and deduction don't tell us anything substantive about the world. For this much more interesting area of knowledge we must rely on 'matters of fact' which might be wrong but are at least more substantive than the truths revealed by rationalism.

Task – p.50 What is the basic difference between rationalism and empiricism? What a priori knowledge will empiricists accept? Are rationalists saying that sense experience cannot give us knowledge?

The simile of the Divided Line

KnowledgeIntelligible Realm OpinionVisible Realm

The simile of the Divided Line KnowledgeIntelligible Realm Opinion Belief (pistis) C Physical things Visible Realm Illusion (eikasia) D Shadows, images, reflections

The simile of the Divided Line Knowledge Intelligence (noesis) A Intelligible Realm Reasoning (dianoia) B Opinion Belief (pistis) C Physical things Visible Realm Illusion (eikasia) D Shadows, images, reflections

Plato: knowledge, the Forms and the physical world Plato denied that sense experience could give us knowledge and he also believed that all knowledge about the world is a priori and innate. He argued that all the things we experience in the physical world are particular examples (rather than perfect concepts) and therefore not the objects of knowledge. For Plato, particular things cannot be objects of knowledge because they will always both be X – have some property, e.g. beauty or largeness – and not-X, either at different times, or to different observers, or in different contexts. For example, we might see a beautiful person in the street or in an advert, but this person is just an example of a beautiful thing - they are not the perfect concept of beauty.

Plato: knowledge, the Forms and the physical world This is clear to us in the fact that another observer might not consider them beautiful at all and in 50 years' time we might not find them so attractive either - so their beauty is changing, impermanent, transient, etc. For Plato, everything in the physical world is like this; there was a time when it didn't exist, a time in the future when it won't exist again; it is subject to decay and death; it is an object of perception and therefore subjective; it doesn't last and therefore it can't give us knowledge. On the other hand, the concept of e.g. beauty does last - and so it is the concept (or Ideal / Form) that Plato believes is enduring and real.

Task – p.51 Explain how Descartes’ wax example shows that knowledge, even of physical objects, relies on reason

Video – Does knowledge depend on experience? After watching the video you will be asked to explain some key ideas you have remembered, so pay attention! Relevance of Newton Billiard balls 17 th century Europe Substantive knowledge White swans

Empiricism Arguments forArguments against