1. Knowledge Empiricism 2

2. Key Terms: A Recap… You need to know what the difference is between:
Analytic and synthetic truths
Necessary and contingent truths
A priori and a posteriori truth

3. Hume divides the areas of human understanding into two camps.
Hume’s fork
Hume divides the areas of human understanding into two camps.
“All the objects of human reasoning or enquiry fall naturally into two kinds, namely relations of ideas and matters of fact.”
work on your own to draw this table and sort which types of truths below are ‘Relations of Ideas’ and which are ‘Matters of Fact’.
Analytic truths
Synthetic truths
A priori truths
A posteriori truths
Necessary truths
Contingent truths
All bachelors are unmarried men
The sun will rise tomorrow
Pythagoras’ theorem
All bachelors are rich men.
Relations of ideas
Matters of fact
Read text together from Hume’s Enquiry.

4. Hume’s fork Relations of ideas Matters of fact Analytic Necessary
A priori
Certain
Examples: Pythagoras’s theorem; All Bachelors are unmarried men.
Synthetic
Contingent
A posteriori
Probable
Examples: the sun will rise tomorrow; all bachelors are rich men.

5. Hume’s empiricism about knowledge
The only truths that we can know independently of experience are analytic truths (i.e. relations of ideas – trivial tautologies that tell us nothing about the world and what exists).
All substantive truths about the world, and what exists in it, must be known by experience.

6. What did you think about the activity on page 157?

7. Strengths of Hume’s empiricism
It is supported by the plausible scientific idea that we need to use observation and experiment to find out about the world outside us.
It explains how we acquire some knowledge independently of experience, by saying that all such knowledge is about things which are internal to us (namely: ideas).
It explains why there always seem to be problems with a priori arguments for substantive truths about the world (e.g. the ontological argument, the trademark argument, Plato’s arguments for the Forms, arguments for the existence of the soul, etc.)

8. Weaknesses of Hume’s empiricism
The main problem is that we may not be able to gain true knowledge of the world through our senses.
Rationalist philosophers argue that our senses are not trustworthy enough to give us reliable knowledge of the world.
The rationalist philosopher Descartes argued for this using his three waves of doubt.

9. Other problems for Hume’s empiricism
It implies that mathematical truths are analytic; but this is questionable: do the ideas of ‘2’ ‘+’ and ‘2’ contain the idea of ‘4’?
It has some trouble with moral truths too, since these seem neither analytic (the idea of ‘murder’ doesn’t contain the idea of ‘wrong’) nor discovered by observation and experiment (we can’t see that something is good/bad, right/wrong).
It may be self-defeating, since the view itself seems neither analytic, nor grounded in sense-experience.

10. ‘Hume’s division of human understanding into Matters of Fact and Relations of Ideas successfully represents how we acquire knowledge.’ Do you agree?
Choose two strengths of Hume’s Empiricism to highlight.
Choose two weaknesses of Hume’s Empiricism to highlight.

11. The Crux of The Issue… What is the difference between knowledge empiricism and knowledge rationalism?
Empiricists claim that all knowledge of synthetic propositions is a posteriori, while all a priori knowledge is of analytic propostions. So, anything we know that is not true by definition or logic alone, we must learn and test through the senses.
Rationalists deny this, claiming that there is some a priori knowledge of synthetic propositions, either because this knowledge is innate or because we can gain such knowledge using reason rather than sense experience.
Many rationalists add that the synthetic a priori knowledge we gain through reason or innately cannot be arrived at in any other way.
They may also argue that it is superior, for example by being more certain, to the knowledge or beliefs we gain through the senses.
Empiricists deny and rationalists assert that we can gain a priori knowledge of synthetic propositions that are about things other than one’s own mind.

12. Page 158 – experimenting with ideas.
Can a priori knowledge tell us about the world?
Empiricist says NO!
They say either 1) all knowledge is a posteriori and a priori knowledge actually does not exist
Or 2) a priori knowledge does exist, but it is all analytic (so tells us nothing about the world)
What do you think?

13. Homework (due next lesson)
Make notes on
1) there is no a priori knowledge at all (p )
And 2) a priori knowledge does exist but is all analytic (p )
Write a paragraph explaining your opinion on the above.

14. Need to demolish it because…
Wave 1
Wave 2
Wave 3
Can’t trust our senses because…
Can’t trust our senses because…
Can’t trust our senses because…
Old System of Beliefs
Need to demolish it because…
HOWEVER
HOWEVER
HOWEVER
Some beliefs remain because…
Some beliefs remain because…
There is still one thing we can be certain of…