Causal Arguments and Correlations

Arguments about Causes

• Students at the front of the classroom tend to get better grades.
• Married people are, on average, happier.
• Wealth doesn't correlate with happiness.
• People with "can-do" attitudes tend to be wealthier.
• Arguments about causes and effects are vital for increasing good effects and preventing bad ones.

Causal Arguments Start with Correlations

• Evidence for claims about causes is usually a correlation.
• Correlation is a regular association between two events or kinds of events.
• The general argument form:
  • Event E1 is regularly associated with event E2.
  • Therefore, event E1 causes event E2.
• Concluding that E1 causes E2 because they are associated.
• Example: People who meditate tend to be calmer, therefore meditation calms people.
• Correlations can be noted in trends, such as increasing violence on television correlating with increasing violence in the real world.
• Inverse correlations can suggest causality.
  • Increased vitamin use correlates with decreased health, suggesting vitamins may be harmful.
• Noncorrelation may imply a lack of cause.
  • Happiness and wealth are not correlated, so money does not bring happiness.
• Exploring correlations is a scientific research strategy.
  • Researchers look for correlates to conditions of interest, like lightning, genius, or colds.

Correlations May Have Alternative Explanations

• Arguments from correlation to cause are often compelling, but have systematic difficulties.
• Correlations may be explained in multiple ways, with unclear underlying causes.
• Some correlations may simply be coincidental.
• Correlation does not establish the direction of the connection.
  • If E1 is correlated with E2, E2 also may cause E1.
  • People with "can-do" attitudes tend to be wealthier, but wealth may cause the attitude.
• Calmer people may be drawn to meditation, rather than meditation causing calmness.
• The correlation suggesting television is ruining morals could mean morals are ruining television.
• Some other cause may underlie and explain both correlates.
  • E1 correlated with E2, but E3 causes both E1 and E2.
  • Students sitting in front getting better grades may be due to special commitment to schooling.
• Multiple or complex causes may be at work in many directions at the same time.
  • Violence on television reflects violence in society, and helps worsen it, along with other underlying causes.

Work Toward the Most Likely Explanation

• With various explanations for a correlation, find the most likely explanation.
• Step 1: Fill in the connections, explaining how each possible explanation makes sense.
• Step 2: Fill in the connections for your favored and alternative explanations.
• Example: Studies correlate increased vitamin use with decreased health.
  • Explanation 1: Vitamins worsen health.
  • Explanation 2: People in bad health use more vitamins to improve.
• Step 3: Determine the most likely explanation.
• Need other information such as whether vitamins can be harmful or not.
• Marriage and happiness correlate. Marriage may make people happier, or happier people may be more successful at getting and staying married.
• The most likely explanation is seldom conspiracy or supernatural intervention.
• The Bermuda Triangle is not supernaturally spooked, but heavy traffic with unpredictable weather.
• Conspiracy theories often leave more unexplained than usual explanations.

Expect Complexity

• Many happy people are not married, and many married people are unhappy.
• Marriage may have an effect on average happiness, but other causes exist.
• If E1 causes E2, if E1 doesn't always produce E2 or another cause also produces E2 it is not a counterexample.
• The claim is that E1 often or usually produces E2.
• It is still possibly E1 is among the major contributors.
• Many different causes may contribute to an overall effect.
  • Some causes of global climate change are natural, but human contributions also have an effect.
• Causes and effects may "loop".
  • Filmmakers' independence may lead to their creativity.
  • Creative filmmakers may seek independence, leading to more creativity.

Deductive Arguments

• Consider the argument: If there are no chance factors in chess, then chess is a game of pure skill; There are no chance factors in chess; Therefore, chess is a game of pure skill.
• Suppose that the premises of the argument are true.
• You can conclude with perfect assurance that chess is a game of pure skill.
• There is no way to admit the truth of these premises but deny the conclusion.
• Arguments of this type are called deductive arguments.
• A properly formed deductive argument is an argument of such a form that if its premises are true, the conclusion must be true too.
• Properly formed deductive arguments are called valid arguments.
• Deductive arguments differ from arguments considered that do not guarantee the truth of the conclusion.
• Nondeductive arguments conclude beyond the premises.
• A valid deductive argument only makes explicit what is already contained in the premises.

Modus Ponens

• Using the letters p and q to stand for declarative sentences, the simplest valid deductive form is
• If [sentence p] then [sentence q]
• [Sentence p]
• Therefore, [sentence q]
• Written more briefly
• If p then q
• p
• Therefore, q
• This form is called modus ponens ("the mode of putting": put p, get q).
• Introductory example follows modus ponens (check it out).
• Second example:
• If drivers on cell phones have more accidents, then drivers should be prohibited from using them
• Drivers on cell phones do have more accidents
• Therefore, drivers should be prohibited from using cell phones
• To develop this argument, you must explain and defend both of its premises.

Modus Tollens

• A second valid deductive form is modus tollens.
  • The mode of taking: take q, take p.
• If p then q
• Not-q
• Therefore, not-p
• "Not-q" simply stands for the denial of q.
• Sherlock Holmes used a modus tollens argument at a key moment in "The Adventure of Silver Blaze."
• An example of Holmes's argument put as a modus tollens:
  • If the visitor were a stranger, then the dog would have barked.
  • The dog did not bark.
  • Therefore, the visitor was not a stranger.

Hypothetical Syllogism

• A third valid deductive form is "hypothetical syllogism."
• If p then q, if q then r, therefore, if p then r.
• Example:
  • When you learn to care for a pet, you learn to attend to the needs of a dependent creature.
  • When you learn to attend to the needs of a dependent creature, you learn to be a better parent.
  • Therefore, when you learn to care for a pet, you learn to be a better parent.

Disjunctive Syllogism

• A fourth valid deductive form is "disjunctive syllogism."
• p or q, not-p, therefore, q.
• Suppose we continue playing detective:
• Either Dorabella or Fiordiligi stole the tarts.
• The implication is pretty clear. Either d or f, not d, therefore, f.
• English word "or" complications.
• "p or q" means that at least one of p or q is true, and possibly both.

Dilemma

• A fifth valid deductive form is the "dilemma."
• p or q, if p then r, if q then s, therefore, r or s.
• Rhetorically, a dilemma is a choice between two options both of which have unappealing consequences.
• Schopenhauer example paraphrased:
• The closer two hedgehogs get, the more likely they are to poke each other with their spikes; but if they remain apart, they will be lonely.

Reductio Ad Absurdum

• One traditional deductive strategy deserves special mention even though, strictly speaking, it is only a version of modus tollens.
• "reduction to absurdity."
• Arguments by reductio (or "indirect proof").
• Establish their conclusions by showing that assuming the opposite leads to absurdity: to a contradictory or silly result.

Deductive Arguments in Multiple Steps

• Many valid deductive arguments are combinations of the basic forms introduced in Rules 22-27.
• Sherlock Holmes performing a simple deduction for Doctor Watson:
  • Watson has a little reddish mold on his boots.
  • If Watson has a little reddish mold on his boots, then he has been to the Wigmore Street Post Office this morning.
• Putting Holmes's deduction into explicit premises:
  • Watson has a little reddish mold on his boots.
  • If Watson has a little reddish mold on his boots, then he has been to the Wigmore Street Post Office this morning.

Explore The Issue

• Begin with the issue but not necessarily a position.
• Do not feel that you must immediately embrace some position and then try to shore it up with arguments.
• Do not just dash off the first argument that occurs to you.
• You are not being asked for the first opinion that occurs to you.
• Asked to arrive at a well-informed opinion that you can defend with solid arguments.

Spell Out Basic Ideas as Arguments

• Constructing arguments: conclusions backed by evidence and reasons.
• Formulate a position, take its basic idea and frame it as an argument.
• Get out a large sheet of scratch paper and literally draft your premises and conclusion in outline.
• Aim first for a relatively short argument-say, three to five premises-using the forms offered in this book.
• Put into a premises-and-conclusion form in this way:
  • 1. There are many solar systems beyond our own.
  • 2. If there are many solar systems beyond our own, then it is very probable that there are other planets like Earth.
  • 3. If it is very probable that there are other planets like Earth, then it is very probable that some of them have life.
  • Therefore, it is very probable that some other planets have life.

Defend Basic Premises with Arguments of Their Own

• Once you have spelled out your basic idea as an argument, it will need defense and development.
• anyone who doesn't know much about the question in the first place-most of the basic premises will need supporting arguments of their own.
• for example, at the argument about life on other planets.
• The argument begins with the premise that there are many solar systems beyond our own.
• The argument begins : -As of 17 February 2017, the Paris Observatory's "Extrasolar Planet Encyclopaedia" lists 3,577 known planets of other stars, including many in multi-planet systems.
• The second premise of the basic argument for life on other planets is that if there are other solar systems beyond our own, then it is very probable that some of them include planets like Earth.

Reckon With Objections

• Too often, when we make arguments, we concern ourselves only with the pro side: what can be said in support.
• Objections tend to come as a shock.
• We realize, maybe a little late, that we didn't think enough about possible problems.
• It's better to do so yourself and to hone your argument maybe even make fundamental changes in advance.
• You already have explored the issue thoroughly and with a somewhat open mind.
• "Even such obviously good ideaas"are going to be met wih objections by some if not many Thoughtful well meaning people will oppose even the obviously good ideas
• Many actions have many effects, not just one.
• Thoughtful and well-meaning people may oppose even such obviously good ideas (obvious to us, anyway) as eating more beans or getting married in order to be happy or sending more students abroad.

Explore Alternatives

• If you are defending a proposal, it is not enough to show that your proposal will solve a problem.
• You must also show that it is better than other plausible ways of solving that same problem.
• Exploring alternatives is not just a formality.
• The point is not just to quickly survey a few boringly obvious, easily countered alternatives and then (big surprise) to re-embrace your original proposal.
• Look for serious alternatives, and get creative.
• Even general or philosophical claims have alternatives.