PHIL 113–Introduction to Philosophy

NOTES TO ENHANCE CRITICAL THINKING

One of the most important skills that a person can develop and refine is the ability to reason well. Each of us, because we are human beings, has the innate ability to construct arguments and draw inferences. However, many people never develop this ability beyond a very basic level. In your study of philosophy, (indeed, in many of the disciplines you might study in college and in any of the careers you might choose to pursue), you will need to develop and refine your ability to reason. Fortunately, humans have discovered and developed an art which directs the innate human ability to construct arguments and draw inferences so that the person constructs sound arguments and draws valid inferences. This art is logic––the art of critical thinking.

Logic: the art of critical thinking.

Each art operates upon some subject matter for the sake of some end; for example, the art of carpentry operates upon building materials such as wood and steel in order to construct things such as bookcases, cabinets, and houses. Logic also operates upon some subject matter. Without getting too complicated, we can identify three basic elements in the subject matter of logic: concepts, propositions, and arguments.

Concept: an idea which represents a collection of things with a nature or property in common.
Proposition: a statement which can be either true or false.
Argument: an ordered set of propositions, one of which is the conclusion, one or more of which are premises.

To explicate the definition of ‘‘argument,’’ note the following additional definitions.
Premise: a proposition which supports another proposition (i.e., a conclusion).
Conclusion: a proposition which is supported by some other proposition(s) (i.e., premise(s)).

Identifying Arguments

When confronted with a passage or when listening to a discussion, it is often difficult to determine whether or not it is an argument. Compare these two passages from Alexis de Tocqueville's Democracy in America:

[1] In America the principle of the sovereignty of the people is neither barren nor concealed, as it is with some other nations; it is recognized by the customs and proclaimed by the laws; it spreads freely, and arrives without impediment at its most remote consequences.

[2] In America the people appoint the legislative and executive power and furnish the jurors who punish all infractions of the laws. The institutions are democratic, not only in their principle, but in all their consequences. . . . The people are therefore the real directing power.

In order to distinguish arguments from other kinds of discourse, it is helpful to distinguish words which frequently (although not always) signify that an inference is being drawn. In English, we have inference signs which indicate that a proposition is a premise and other inference signs which indicate that a proposition is a conclusion. The following list, which is not
exhaustive, indicates examples of each kind of inference sign:
Premise Indicators:                                                                                              Conclusion Indicators:
            Since                                                                                                                      Therefore
            Because                                                                                                                   So
            For                                                                                                                          Consequently
            On account of                                                                                                          Thus
            Given that                                                                                                                Hence
            Assuming that                                                                                                          It follows that
Using these inference signs as guides, we can see that the second passage from Tocqueville is an argument. The conclusion, which is indicated by the word ‘‘therefore,’’ is that the people are the real directing power. The first passage gives a description of America but the propositions are not ordered in such a way that one is supported and the others are supporting. Caveat: This is not to say that every argument has inference signs which indicate premises or conclusions.

Exercises in Identifying Premises and Conclusions

A. In each of the following exercises, circle the inference sign and underline the conclusion.

1. Defenseless herrings herd together because predators cannot focus their attention on any one target.

2. The moon always has the same side towards the earth, since it rotates on its axis just once during a revolution around the earth.

3. Music can create a variety of moods in listeners, therefore it can enhance many dramatic productions.

4. Partly on account of their lacking a regular crystalline structure, ceramic materials are poor conductors of electricity.

5. Fish have no iris to control the amount of light that enters their eyes, hence they are found at different depths during a sunny day.

6. When good quality steel is deformed it recovers its original configuration, consequently it is a good example of an elastic material despite its inability to stretch and bend.

7. Dogs respond more to the emotional tones in the human voice than the words that are spoken, for when one says two contradictory sentences in the same emotional tone their behavior is the same.

8. There are twenty amino acids and sixty-four triplet codes; it follows that some of the amino acids are represented by more than one code.

9. Considering the fact that they are both very gentle people, they should have no trouble getting adjusted to one another after they are married.

10. Infrared waves have lower frequencies and therefore greater wavelengths than do red waves.

11. Brains of domesticated rabbits are considerably smaller than those of wild rabbits. This may be attributed to their lack of exercise of the intellect, instincts, senses and voluntary movements and also because they are closely confined.

12. Money is the most important thing in the world since it represents health, strength, honor, generosity, and beauty as conspicuously as the lack of it represents illness, weakness, disgrace, meanness, and ugliness.

B. In each of the following exercises, determine if the passage is an argument and, if so, indicate what the conclusion is.

1. We fancy that this din of religion, literature and philosophy, which is heard in pulpits, lyceums, and parlors, vibrates through the universe and is as catholic a sound as the creaking of the earth's axle; but if a man sleep soundly, he will forget it all between sunset and dawn.  It is the three-inch swing of a pendulum in a cupboard, which the great pulse of nature vibrates by and through each instant (Henry David Thoreau).

 2. Now each person judges well the things he knows, and of these he is a good judge.  And so the person who has been educated in a subject is a good judge of that subject, and the person who has received an all-round education is a good judge in general (Aristotle).

 3. I do not think that one should have children.  [Because] I observe the acquisition of children has many risks and many griefs, whereas a harvest is rare, and even when it exists, it is thin and poor (Democritus).

 4. There is widespread opinion that we do not need to pray, since God knows our needs better than we do. . . .  But subjectively, prayer is indeed necessary, i.e., for our sakes.  The reason is that to grasp and comprehend what he is thinking, a person needs to clothe his thoughts in words, and if he wants to produce for himself a lively representation of his affection and trust in God, he needs to have recourse to words  (Immanuel Kant).

5. You express a great deal of anxiety over our willingness to break laws.  This is certainly a legitimate concern. . . . One may well ask: “How can you advocate breaking some laws and obeying others?”  The answer lies in the fact that there are two types of laws: just and unjust. .  .  . One has not only a legal but a moral responsibility to obey just laws.  Conversely, one has a moral responsibility to disobey unjust laws  (Martin Luther King, Jr.).

6. The history of the present king of Great Britain is a history of repeated injuries and usurpations all having the direct object the establishment of an absolute tyranny over these states.  To prove this, let the facts be submitted to a candid world.  He has refused his assent to laws most wholesome and necessary for the common good.  He has forbidden his governors to pass laws of immediate and pressing importance, unless suspended in their operation till his assent be obtained; and when so suspended, he has utterly neglected to attend to them. . . . He has dissolved representative houses repeatedly for opposing with manly firmness his invasions of the rights of the people. (Thomas Jefferson).

7. There are three possible parts to a date, at least two of which must be offered: entertainment, food, and affection.  It is customary to begin a series of dates with a great deal of entertainment, a moderate amount of food, and the merest suggestion of affection.  As the amount of affection increases, the entertainment can be reduced proportionately.  When the affection is the entertainment, we no longer call it dating. Under no circumstances can the food be omitted (Judith Martin).

8. The power of acquiring and disposing private property is necessary for human life, for three reasons.  First, because everyone is more careful to procure something that concerns oneself alone than something that is common to all or many others.  (For each one, escaping work, leaves for others any common task, as happens when there are a great many officials.)  Second, because human affairs are handled in a more orderly fashion when each one goes about one’s own business. There would be complete confusion if everyone tried to do everything.  Third, because this leads to a more peaceful condition for humans, while everyone is content with what he or she has.  For we see that among those possessing something in common, disputes arise more often (Thomas Aquinas).

9. [One type of feminism is liberal feminism.] Liberal feminists find the roots of women’s oppression in those cultural constraints that hinder women from competing in the public world. . . .  Because traditional society holds the false belief that women are, by nature, less mentally and physically capable than men, it largely excludes women from the academy, the forum, the marketplace.  Excluded from the land of opportunity, women are unable to demonstrate their capabilities: This is a discriminatory state of affairs.  Therefore, liberal feminists insist that society should give women the same educational and occupational opportunities that men have. . . (Rosmarie Tong).

10. If Protagoras is correct when he wrote that ‘the human is the measure of all things: of things which are, that they are, and of things which are not, that they are not’ then false judgment is impossible.  But false judgment is possible, for the following reasons: most people believe that false judgment is possible, and they are either correct or incorrect.  If they are correct, then false judgment exists.  But if they are incorrect, then their judgment that false judgment exists is itself false and so false judgment exists.  Therefore, Protagoras’ position is incorrect. (Adapted from Plato).