Critical Thinking

Critical Thinking Philosophy as a set of skills

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

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

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

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  Q Q  P Types of Arguments

Modus tollens P  Q ~Q ~P Not to be confused w/ denying the antecedent P  Q ~P  ~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) Deductive Arguments (cont’d.)

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 Types of Arguments: Inductive arguments

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

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 Types of Arguments: Fallacies

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 Fallacies: formal

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

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’) Types of Arguments: Informal fallacies

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 Informal fallcies (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 Informal fallacies (cont’d.)

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.

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.

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.

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.

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.

Critical Thinking