1. Arguments and other tools

2. Reasoning The primary tool of the philosopher is reasoning.
In order to have a well-reasoned position, you have to understand the arguments both for and against that claim.

3. What Is an Argument?
An argument is a reason or set of reasons that provide support intended to establish the truth of some claim.
An argument has two main parts:
One or more premises (reasons or evidence given in support of some claim) and
A conclusion (the claim being supported)

4. Uses Arguments are used as a means of inquiry and
Arguments are used to defend a particular position.

5. Evaluating Arguments
The focus in evaluating an argument is primarily on the premises and how they hook up with the conclusion.
Thus, to evaluate an argument you must first clearly identify the premise(s) and the conclusion.

6. Evaluation, cont. Four things you should look for:
Are the premises relevant to the truth of the conclusion?
Do the premises provide enough support to warrant accepting the conclusion?
Does the argument rely on unsupported assumptions or ignore relevant facts?
Are the premises true?

7. Refutation
An argument is refuted if it is shown that the premises are irrelevant, the premises are not strong enough, or at least one of the premises is false.
Simply rejecting the conclusion does not constitute a refutation.

8. Counter-Argument
A counter-argument is an argument for the opposite conclusion.

9. Thought Experiments
Hypothetical cases intended to isolate intuitions about a particular ethical issue.
The contrived/controlled nature of thought experiments is analogous to scientific experiments.

10. Consider…
The following cases are adapted from an example in: James Rachels, "Active and Passive Euthanasia," New England Journal of Medicine 292 (1975):
Case 1:
A nephew knows that if his uncle dies he’ll inherit lots of money. The nephew cares more about the money than he does the uncle so decides to kill him for the inheritance. Upon making this decision, he goes to his uncle’s house, finds him in the bath and holds his head under water until he dies.

11. And compare…
Case 2:
A nephew knows that if his uncle dies he’ll inherit lots of money. The nephew cares more about the money than he does the uncle so decides to kill him for the inheritance. Upon making this decision, he goes to his uncle’s house. As he arrives the uncle slips, hits his head on the tub, and slides under the water. The nephew could save him, but chooses not to.

12. Counter-examples
An uncontroversial case that undermines a general claim is a counter-example.
For any universal generalization, one good counter-example can show that it is false.
Consider the claim: “It’s always wrong to lie.” - Can you think of a counter-example?