Our Logic Series began by examining the foundation of beliefs and then explored deductive and inductive arguments, fallacies and experiments. We continue our study by understanding and criticizing theories.
Theories: Choosing the best theory to understand phenomena
What happens when something happens with no certain cause? Human curiosity often compels people to form opinions as to the cause of the phenomena that surround them. You might be familiar with theories that explain the origin of the universe as well as the debate that surround them. In court, prosecution and defense attorneys craft theories to explain the behaviors and events that led to a particular outcome.
Sometimes, two competing theories exist that are mutually exclusive. In many cases, three or more theories might exist that could explain the same phenomenon. Logic seeks to choose the best theory out of two or more competing theories. By following some practical guidelines, you can choose the theory that is most suitable in any particular setting:
Testable. A theory, by definition, must be testable in principle.
Likelihood. You should select the one theory that seems to be the most likely to be true.
Simplicity. Choose the simplest of the theories that explain a particular event. Conspiracy theories are often rejected because of their complex collation of a variety of underlying suppositions.
Scope. If one theory explains a single phenomenon and a competing theory explains five phenomena, Choose the theory that has the greatest range or scope. Newton’s theories about physics explained motion on earth and in the heavens and was, therefore, chosen above theories of Kepler and Galileo that explained only one event.
Criticizing a theory
If you choose to argue against a theory, criticize it by creating another theory that has similar likelyhood, simplicity and scope. You can also question the assumptions used to create a need for a theory. For example, you might criticize a theory that explains why the sky is blue by asking, “Is the sky blue?”
Suppose you were a football star and you wanted to create a theory about why you play football so well. Your theories might include the following:
Your DNA predisposes you to play football well.
You say that you are a good football player so that necessarily means that it is so.
You practice a lot.
The likelihood, simplicity and scope of the theory, “I am a good football player because I practice a lot,” would warrant its selection. To criticize that theory, I might ask the question, “How do I know that you are a good football player?”
As another example, suppose I proposed a theory about why water boils at 180℉. Without discussing the details of my theory, you could simply challenge my assumption, saying that water does not boil at 180℉.
Show that a theory is illegitimate
You can cause your audience to reject a theory by showing that it is irrelevant or illegitimate for one of the following reasons:
The theory lacks causal relevance.
The theory is inconsistent with known physical laws.
The theory is not testable in principle.
The theory leads to a false consequence.
An alternative theory exists that is at least as likely, simple and powerful as the one in question.
The theory explains a non-existent phenomenon.
Consider the theory that the occurrence of home invasions has decreased because of gun ownership. To criticize the theory, you could ask the following questions:
Q1. Is it a legitimate theory?
Q2. Does it lead to a false prediction? (does it lead to a theory you know is false?)
Q3. Is there an alternative theory?
Q4. Does the phenomenon exist?
A theory that states that birds, just like me, long to be close to you might explain why birds suddenly appear whenever you are near?
Q1. Is the theory testable? Probably not.
Q2. is there an alternative theory? Probably.
Q3. does the phenomenon exist? Probably not.
Suppose a man discovers that his sandwich is missing from the refrigerator. He might craft any of the following theories:
My wife took my sandwich.
My dog got my sandwich.
Someone broke into my house, went to the kitchen, found my sandwich in the fridge and took it.
Each of my theories meets the necessary conditions of a theory, so we cannot reject any of them out of hand. The next step is to evaluate the competing theories based on likelihood and simplicity. If the man’s dog was known to be in a fenced area for the entire history of my sandwich, the theory that his wife took the sandwich instantly gains credibility.
We could criticize the theory by questioning whether the sandwich ever existed. We could also suggest that the sandwich did not belong to the man. Finally, we could argue that the sandwich is not really missing.
Now, suppose we proposed two theories to explain how the man’s wife took his sandwich:
His wife took his sandwich by putting on latex gloves and using tongs to grab his sandwich from the fridge.
His wife took the sandwich by opening the fridge and grabbing the sandwich with her hand.
Theories attempt to explain things that are not easily understood. By comparing competing theories and applying logical rules, you can choose the theories that make the most sense and offer the most plausibility.
Share your thoughts about theories by sending an email to email@example.com.