1. Philosophy as a set of skills
Critical Thinking
Philosophy as a set of skills

2. As the method of philosophy, solving philosophical problems involves
Identifying basic beliefs
Clarifying basic beliefs
Formulating the problem
Identifying possible solutions
Gathering information
Recognizing assumptions and points of view
Defending possible solutions
Forming a reasoned judgment

3. Skills of Critical Thinkers; Critical Thinkers Can
Clarify concepts and beliefs
Recognize and formulate problems
Identify possible solutions
Gather relevant information
Be aware of their assumptions, points of view, and biases
Identify, formulate, & evaluate arguments
Weigh the merits of possible solutions
Evaluate the merits of possible solutions
Examine the consequences of accepting a solution

4. Traits of Critical Thinkers; Critical Thinkers are
Analytic
Confident
Inquisitive
Persistent
Systematic
Tolerant
Truth-seeking

5. Types of Arguments
Deductive arguments: in a valid deductive argument, the conclusion must be true if the premises are true. ‘soundness’ is what is required (that is, valid argument + true premises)
Modus ponens
P  Q P Q
Not to be confused w/ affirming the consequent
 P

6. Deductive Arguments (cont’d.)
Modus tollens
P  Q ~Q ~P
Not to be confused w/ denying the antecedent
 ~Q
Disjunctive syllogism
P or Q ~P Q
(note that disjunctions don’ t have to be exclusive, that is, either this or that but not both)

7. Types of Arguments: Inductive arguments
In a valid inductive argument, conclusions are presented as probable -- not necessary, that is, if the premises are true (or probable), the conclusion is only probably true
In these cases we’re looking, not for soundness (in the deductive sense,) but evaluating the relevance, adequacy, and sufficiency of the premises

8. Inductive arguments (cont’d.)
Analogy
A is like B
B has property x
 A (probably) has property x
Evaluation focuses on the degree of supposed similarity

9. Inductive arguments (cont’d.)
Causal argument
A is correlated with B
Nothing else is known to be the cause of B
 A is likely to be the cause of B
Evaluation focuses on the second premise, that is, on the claim that other possible causes can be eliminated from contention

10. Inductive arguments (cont’d.)
Abduction
A exists
B is the best explanation of A
 B probably exists
Also called “inference to the best explanation”, evaluation focuses on “best explanation” from relevant alternatives and on degree of ‘explanatory power’

11. Inductive arguments (cont’d.)
Inductive generalization
All A’s examined so far have property x
This is an A
 A probably has property x
Evaluation focuses on number of observations (relative to total size) as well as carefulness of observation

12. Inductive arguments (cont’d.)
Statistical generalization
N% of A’s examined so far have property x
This is an A
 This has an N% chance of having property x
Evaluation focuses on size of sample, distribution of sample, obversational technique

13. Types of Arguments: Fallacies
Fallacies are arguments where the premises are meant to serve as support for the conclusion, but where they don’t in fact (deductive fallacies) or where they don’t with sufficient probability
These can be divided into ‘formal fallacies’, where the ‘form’ of the argument is faulty, or ‘informal fallacies’, where the premises are, in some measure, irrelevant

14. Fallacies: formal Begging the question P  P
Sometimes called a “circular argument” , the problem lies in (sometimes unknowingly) assuming what needs to be proved, or introducing the conclusion as a premise

15. Formal fallacies (cont’d.)
Affirming the consequent
P  Q Q
 P
Denying the antecedent
P  Q ~P
 ~Q

16. Formal fallacies (cont’d.)
Post hoc ergo propter hoc
Literally, “after this, therefore because of this”
The problem here lies in assuming that because two events follow upon one another, that therefore they are causally related -- a typical fallacy in historical arguments

17. Formal fallacies (cont’d.)
Hasty generalization
When a generalization is made from too small a sample or too cursory a set of observations
Equivocation
When a term is used in an argument with at least two senses, or when amibiguity is exploited to lead to a desired conclusion

18. Types of Arguments: Informal fallacies
Ad hominem
Literally, “against or to the man” -- when appeal is made to the character (or other irrelevant characteristic) of the person making or opposing the argument
Appeal to authority
When the status of an individual making a claim is used to confirm the truth or probability of that claim (distinct from ‘expert testimony’)

19. Informal fallcies (cont’d.)
Tu quoque
Literally, “you’re another”, when appeal is made to the fault of another as defense for a similar fault
Straw man
When an argument or claim is construed or interpreted in the weakest possible way, so as to make it easy to undermine it

20. Informal fallacies (cont’d.)
Red Herring
When appeal is made to irrelevant considerations, in order to shift attention or focus from the claim at issue
Appeal to ignorance
When it is claimed that something is true, probable, or plausible in virtue of the fact that it cannot be shown to be or is not known to be false

21. Example 1
In every conflict, the respective governments or groups claim to be fighting for justice. But “justice” is just a word, and fighting over words is silly (in the case where people get killed, it is criminal.) Therefore all conflicts or wars are unjustified, and both sides in whatever conflict are wrong.

22. Example 2
Israel has no moral right to condemn acts of Palestinian terrorism because it too makes use of morally reprehensible acts to defend itself. Its security services are allowed by law to torture criminal suspects. It indiscriminately targets innocent civilians in order to eliminate terrorists. And, in any event, many of its leaders have been terrorists or war criminals themselves.

23. Example 3
Monsanto and other companies which promote genetically-modified foods are acting irresponsibly. We don’t know what the effects of introducing these new plants into the environments will be. These companies are trying to increase profits by gambling on our future. Besides, we don’t particularly need these genetically-modified variants when natural versions are perfectly adequate.

24. Example 4
Everybody knows that giving people handouts only leads to dependence on those handouts. We, as a state, can’t afford to have a group of people forever dependent on public funds. So it follows that welfare rates should be kept at the absolute minimum for survival in order to encourage people to work and reduce the cost to public. It’s the only thing we can do, given a limited public purse.

25. Example 5
The only legitimate approach to treating drug addiction, of any kind, is complete abstinence. If even one slip is allowed, then it is impossible to condemn any subsequent slips. Pretty soon, for instance, one drink becomes many, and the long slide back into alcoholism becomes inevitable.