1. Methods and Interests

2. Argument Argument is at the heart of philosophy
It is the only method for getting results
The nature of the method is also of interest
We seek abstract knowledge of arguments
Allows knowledge of particular arguments
Is studied in Logic (Formal and Informal)

3. Argument Let’s look at how we talk about arguments
This will make future discussions less scary as the way we discuss things will be familiar to you
And will leave you able to follow the content of the discussion without having to struggle with the form

4. Logic Matters The argument in the Euthyphro was basically this:
Socrates gets from Euthyphro a definition of ‘piety:’ Piety is what the gods love and impiety what the gods hate.
Socrates then derives certain consequences of this definition. Specifically: the same things are both pious and impious
Finally deriving the conclusion that: Piety is not what the gods love nor impiety what they hate.

5. Logic Matters I claim this involves an argument of the form
If A then B
Not B
Not A
This form is called modus tollens
Let’s look at this form

6. Logic Matters
Here’s an example
If A then B
Not B
Not A

7. Logic Matters Here’s an example If it has rained then the grass is wet
Not B
Not A

8. Logic Matters Here’s an example If it has rained then the grass is wet
The grass is not wet
Not A

9. Logic Matters Here’s an example If it has rained then the grass is wet
The grass is not wet
It has not rained
If the reasons are true the conclusion must be true

10. Logic Matters
Here’s another example
If A then B
Not B
Not A

11. Logic Matters Here’s another example
If Socrates is a man then he is mortal
Not B
Not A

12. Logic Matters Here’s another example
If Socrates is a man then he is mortal
Socrates is not mortal
Not A

13. Logic Matters Here’s another example
If Socrates is a man then he is mortal
Socrates is not mortal
Socrates is not a man

14. Logic Matters Any modus tollens argument is a like that
Why do we say the Euthyphro argument was modus tollens?
Because it looks like this:

15. Logic Matters
If piety is what is loved by the gods then the same things are both pious and impious.
The same things are not both pious and impious

16. Logic Matters
If piety is what is loved by the gods then the same things are both pious and impious.
The same things are not both pious and impious
Piety is not what is loved by the gods

17. Logic Matters
If piety is what is loved by the gods then the same things are both pious and impious.
The same things are not both pious and impious
Piety is not what is loved by the gods
We know the second premise is true
Because we know any contradiction must be false

18. Logic Matters
If piety is what is loved by the gods then the same things are both pious and impious.
The same things are not both pious and impious
Piety is not what is loved by the gods
We know the first premise is true
Because we agreed to each step of the argument that derived the ‘then’ part from the ‘if’ part

19. Logic Matters
If piety is what is loved by the gods then the same things are both pious and impious.
The same things are not both pious and impious
Piety is not what is loved by the gods
We know the conclusion is true
Because we see that the argument is modus tollens and we know it has true premises

20. Science Matters This kind of argument has a role in Science
It is part of the method that scientists use to seek answers to such questions as
Why do needles point north?
Why do sticks bend going into water?
Why does water boil when heated?
Science has earned great respect as a way of getting at the truth of things
So its methods should be valued

21. Science Matters
How do scientists seek answers for questions about the world?
They apply the Hypothetico-Deductive Method
Form a hypothesis
Deduce testable consequences from the hypothesis
Test for these consequences
Confirm or disconfirm the hypothesis

22. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
Form a hypothesis
Deduce testable consequences from the hypothesis
Test for these consequences
Confirm or disconfirm the hypothesis

23. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
There were land bridges across the oceans
Deduce testable consequences from the hypothesis
Test for these consequences
Confirm or disconfirm the hypothesis

24. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
There were land bridges across the oceans
There would be remains of those bridges
Test for these consequences
Confirm or disconfirm the hypothesis

25. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
There were land bridges across the oceans
There would be remains of those bridges
There is no evidence of these bridges
Confirm or disconfirm the hypothesis

26. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
There were land bridges across the oceans
There would be remains of those bridges
There is no evidence of these bridges
Land bridges didn’t cross the oceans

27. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
Form another hypothesis
Deduce testable consequences from the hypothesis
Test for these consequences
Confirm or disconfirm the hypothesis

28. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
The continents were previously joined but split up
Deduce testable consequences from the hypothesis
Test for these consequences
Confirm or disconfirm the hypothesis

29. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
The continents were previously joined but split up
The continents are moving
Test for these consequences
Confirm or disconfirm the hypothesis

30. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
The continents were previously joined but split up
The continents are moving
Measurements show that they are moving
Confirm or disconfirm the hypothesis

31. Science Matters
Example: Why do we sometimes see the same collections of fossilized plants and animals on opposite sides of oceans?
The continents were previously joined but split up
The continents are moving
Measurements show that they are moving
The continents could have split up

32. Science Matters
The similarity of the Hypothetico-Deductive Method and the method of elenchus is clear
The method is not what distinguishes Philosophy
Philosophers see themselves as engaged in the same pursuit of truth as the scientists

33. Science Matters Philosophy is prior to science in that pursuit
Many scientific topics were originally philosophical
physics, astronomy, cosmology, chemistry, biology, …
When do they become sciences rather than philosophies?
When they begin to ask questions whose answers can be found by inspecting the world
Philosophy is needed to discover which parts of a topic asks questions that can be answered in that way

34. Conceptual clarity
So what does philosophy do if it doesn’t ask questions that the world can answer?
It clarifies concepts and allows other methods of enquiry to go forward. Science depends on this.

35. Conceptual clarity Example 1.
The Greeks couldn’t see how motion was possible
For something to move everything at the destination must move
For everything at the destination to move there must be somewhere to go where there is nothing
But everywhere there is something
So motion is impossible
We think this argument is nonsensical. Why did the Greeks have problems?

36. Conceptual clarity Example 1.
The Greeks did not distinguish space and matter
We think of matter as occupying space
They thought of matter as constituting space
They conceived of space and matter as being like a brick wall
Where there was no matter there was not empty space: there was just nothing

37. Conceptual clarity Example 2.
Early scientists couldn’t ‘understand’ Newton’s force of Gravity
For one body to cause a change in another there must be contact
The moon and the earth are not in contact so neither could affect the other
So Gravity is impossible

38. Conceptual clarity Example 3.
We don’t ‘understand’ the nature of matter
Sometimes it behaves like particles
Other times it behaves like waves
It isn’t just ambiguity
Matter seems to be aware of the situation it is in and behaves appropriately
That is absurd, and yet:

39. Conceptual clarity
There’s a more basic reason to value clear and well-formed concepts
We are intentional actors
We act rationally on our beliefs in order to satisfy our desires
To apply reason to our beliefs and desires these need to be concepts
To be successful intentional actors our concepts need to be clear and well-formed