The Evolutionary Origins of Reasoning

"I thought to myself: I am wiser than this man; neither of us probably knows anything that is really good, but he thinks he has knowledge, when he has not, while I, having no knowledge, do not think I have." ― Plato, Apology

Andy Norman Researcher Carnegie
Mellon University

"The human capacity for reason probably evolved to align our mental states both with circumstances in the world and with the mental states of others"

Socrates... was the first to call philosophy down from the heavens and locate her in cities, and even introduced it into homes, and made [people] search about life and customs, and about things good and bad." (Tusculan Disputations, 5.4.10-11, by Cicero 106-43-b.c.)

Socratic Platonism is distinctive in that it is able to start from the very ordinary everyday perceptions of non-philosophers (such as Socrates met on the streets of Athens), and use this as a basis for arriving at a very otherworldly worldview. Socratic/Platonic reasoning is a particular method of critical reasoning. Your first graded paper must show that you understand this method well enough to practice it, focusing on a virtue of your choice.

Reasoning : Socratic reasoning consists in mentally moving from perceptions of specific, concrete, externally visible behavior, to the formulation of virtue-concepts that are more general and abstract, describing internal/invisible character traits. Virtue-concepts are more general than specific behavior, in that the same virtue such as "kindness" can manifest itself in many different specific behaviors.

Virtue-concepts describe things that, unlike visible external conduct, are internal and not directly visible. A kind person will act kindly when the situation calls for it, but the kind action is not the essence of the virtue of kindness, only its external manifestation. For example, on the one hand, a person can imitate the actions of a kind person without really having the habitual motivations and attitudes that constitute kindness as a character trait. And on the other hand, a kind person does not cease being a kind person if she is temporarily paralyzed or stranded on a desert island with no opportunities to show her kindness in action. Treatments of Buddhism and Christianity

A- Concrete examples and easy-to-understand concepts of goodness are our only direct source of knowledge of virtue. They are most readily accessible to understanding, but also imperfect in their ability to represent something only and always admirable. Platonic Forms are pure and precise representations of what is only and always admirable, but they are hardest to grasp, and least readily accessible to understanding. We only come to know them by using concrete examples and familiar concepts as starting points. The way we come to know them is by generalization from, and refinement of, our perceptions of concrete admirable examples. Plato expresses this point in the image of a ladder. In the case of courage, for example, concrete examples of admirably courageous actions lie at the bottom of the ladder, are easiest to understand, and are the indispensable source of all our knowledge of courage. But rules for how to act courageously in concrete circumstances can never capture the essence of admirable courage. The perfect essence of admirable courage - the Platonic Form of courage lying at the top of Plato's Ladder -- is much more difficult for human understanding to grasp. A person trying to understand the perfect essence of admirable courage cannot begin by leaping to the top of the ladder, but must start at the bottom with concrete examples.

Another analogy: Pure silver exists in silver ore, but it exists there in an impure way, mixed with other things. We get pure silver by starting with impure silver ore and refining it to extract the pure silver from the rest of the materials in the ore. In the same way, it can be said that pure goodness exists in our perceptions of goodness in concrete cases. But no particular concrete case represents something purely, only and always admirable. Platonic reasoning is a process of mentally extracting pure and perfectly refined concepts of goodness from these imperfect concrete representations.

I will call this "The Principle of Analogy" because it was the basis for the Medieval doctrine of Analogy explaining how knowledge of God is possible. E.g. Perfect divine love is difficult to understand because it is unlike imperfect human love. But it is also something like, or "analogous to" imperfect human love. So examples of imperfect human love can serve as the "bottom rungs" on Plato's ladder, giving us the first steps on the mental ascent to understanding perfect divine love. It can also be called the principle of "Participation" because it is connected to Plato's ideas that concrete/imperfect reality "participates in" the perfect Forms.

"I thought to myself: I am wiser than this man; neither of us probably knows anything that is really good, but he thinks he has knowledge, when he has not, while I, having no knowledge, do not think I have." ― Plato, Apology With the election cycle in full swing, heated political arguments are constantly brewing. We're inundated with messages designed to persuade us to choose a side. But this is nothing new. In fact, according to new research from Carnegie Mellon University's Andy Norman, the urge to convince others has evolutionary roots.

In a paper recently published in Biology & Philosophy, Norman argues that reasoning is biologically unique to humans. Though other animals draw inferences, only people are able to produce and respond to what he describes as "reason-giving performances." He says this trait allowed our ancestors to build and maintain shared outlooks — a necessity for collective societies in which groups hunted for food together, for example.

"The human capacity for reason probably evolved to align our mental states both with circumstances in the world and with the mental states of others," said Norman, adjunct faculty in the Dietrich College of Humanities and Social Sciences' Philosophy Department. Andy NormanNorman's intentional alignment model (IAM) expands on the argumentative theory of reason (ATR) developed by philosophers Hugo Mercier and Dan Sperber as an explanation for cognitive biases and groupthink. In "Why We Reason: Intention-Alignment and the Genesis of Human Rationality," Norman proposes that reason evolved because it helped — and continues to help — promote mutually advantageous collaboration.

"Natural selection appears to have 'designed' our reasoning propensities to serve dual ends. They function to help us understand the world, but they are also 'for' forging shared outlooks — for building and maintaining points of view that are functionally aligned," he said.

Norman believes that understanding the functional role of reasoning has implications for a wide variety of disciplines, including biology, cognitive psychology, anthropology, philosophy, politics and ethics. And on a more fundamental level, it offers insight into the ways that humans think and behave.

He added, "We use reason to advance various proximal ends, but in the main, we do it to overwrite the beliefs and desires of others: to get others to think like us."

Am I Your Teacher?

Begin by writing "I am the teacher of this class" (or "I am the presenter" or whatever would be most appropriate for your setting) at the bottom of the board with a line drawn above it. Ask the students or participants to show by raising hands how many of them think this statement is true. Presumably, all of them will. If so, ask them why they think this. As they give reasons, write the reasons on the board above the line. Once there are a large number of reasons on the board, ask them what everything written on the board together is called. The purpose is to illustrate that an argument is being made. I told you that I am the teacher. I am standing at the front of the class.

I am leading this exercise.

I am the only adult in the room.

I am the teacher of this class

Ask the students or participants why they think you had them do this as the first exercise when exploring philosophy. Lead a brief discussion. A few points to try to develop during the discussion include:

What you have written on the board is an example of an argument Arguments are the way we think and reason—when we're reasoning something out, what we're doing is forming a series of arguments in our heads

Philosophy is essentially a process of thinking systematically about difficult and interesting questions, and a primary component of philosophy centers on making and evaluating arguments.

What are the two different concepts of "argument" presented in the skit?

The two concepts are:

Mere contradiction or a dispute (Yes it is… No it isn't… Yes it is… No it isn't…) (Proposed by the customer) "A collected series of statements to establish a definite proposition."

When we talk about arguments as used by philosophers, we are talking about an argument in the latter sense. Again, doing philosophy is essentially a process of making and evaluating arguments.

Parts of an Argument

Return to the "I am the teacher of this class" argument. You'll use it as an example to illustrate and help explore what arguments are and how they work.

In a group discussion, explore the parts of an argument. As you do so, it will be helpful to develop the following points and to introduce the following terms:

Ask what parts constitute an argument. What are its basic building blocks? Arguments are composed of sentences. In fact, they are made up of a particular type of sentence, known as a proposition.

Proposition: A declarative sentence that has a truth value. In other words, a proposition is a sentence that can be either true or false. To be precise, propositions express facts about the world that can either be true or false. Examples include "Today is Monday." and "It's raining outside."

Question: Are there kinds of sentences that are not propositions? Answer: Yes. Questions, commands, exclamations, etc., are all types of sentences that are not propositions because they lack a truth value. Examples include "Go open the door," and "What is today's date?"

Typically, most of the propositions in an argument state facts or provide information which support the claim being made. These propositions are known as premises.

Premise: A proposition serving as a reason for a conclusion.

The claim being made is known as the conclusion of the argument.

Conclusion: A proposition that is supported or entailed by a set of premises.

Arguments always have one conclusion, but the number of premises can vary quite a bit. The "I am the teacher of this class" argument has several premises.

Question: Can there be an argument with only one premise? Answer: Yes. For example, "Bill is an unmarried male. Therefore, Bill is a bachelor."

Question: Can there be an argument with no premises? Answer: Yes. For example, consider an argument with no premises and the following conclusion: "It is either Monday in Tokyo or it is not Monday in Tokyo."

It's worth noting that adding premises doesn't necessarily add support for a conclusion. For example, the argument above with no premises is in fact a compelling argument, since it always has to either be Monday or not be Monday in Tokyo.

Now we can say what an argument is in a more precise way:

Argument: An argument is a set (a collection) of propositions in which one proposition, known as the conclusion, is claimed to derive support from the other propositions, known as premises.

To summarize:

Arguments are the way we think and reason—when we're reasoning something out, what we are really doing is forming a series of arguments in our heads.

Though "argument" can also mean a dispute in common use, that's not the sense in which we mean it when doing philosophy. Arguments consist of a conclusion and (almost always) some premises. The conclusion is what the argument is meant to support as being true; it's the claim being made. The premises provide support for the conclusion. There can be any number of premises, from 0 to an infinite number (but having more premises doesn't necessarily mean there is more support for the conclusion!).

The premises and conclusion are propositional statements; that is, they are sentences that express facts (propositions) about the world that may be true or false.

Argument Dissection

The "I am the teacher of this class" argument is in normal form. That's just a fancy way of saying that the premises have been collected together in a list with the conclusion following them. Often, we separate the conclusion from the premises by drawing a line between them (or by putting in the symbol \, which means "therefore," before the conclusion) to make it very clear which proposition is the conclusion. Usually arguments written in English prose are not so simply presented. The conclusion may be stated first, or for stylistic reasons it might not be at either the beginning or the end of the prose. Converting an argument from English prose into normal form allows us to clearly pick out the premises and conclusion.

How can we identify the premises and conclusion of an argument in ordinary prose? It can take some judgment, but we are usually guided by indicator words. The propositions in arguments are often accompanied by words that indicate whether that proposition is a premise or a conclusion.

As a group, brainstorm words or phrases that might indicate that the proposition they introduce is a premise or a conclusion. The following lists provide some of the most common premise and conclusion indicators.

Premise Indicators: since, because, for, in that, as, given that, for the reason that, may be inferred from, owing to, inasmuch as

Conclusion Indicators: therefore, consequently, thus, hence, it follows that, for this reason, we may infer, we may conclude, entails that, implies that.

With that background in hand, the next activity will help everyone see that arguments are in fact all around us and help them to identify more easily the structure of those arguments, which is an important first step in evaluating whether we should be convinced by the argument.

Hand out to each student or participant a couple of arguments you have found in editorials, blogs, philosophy texts, or wherever. Ask them to re-write the arguments in normal form, identifying the premises and the conclusions. When done, ask everyone to pair up. Each person should show his or her partner the original arguments and the rewritten arguments in normal form. Each pair should then discuss whether or not the premises and conclusions were correctly identified. Float throughout the room and answer questions.

Evaluating Arguments

This is a fun activity to help everyone start thinking about how to evaluate whether we should be convinced by an argument. Begin this activity by showing the Monty Python clip, "She's a Witch!" The clip can be found here:

Begin a discussion about whether people are convinced by the argument provided in the video clip. Try to focus the discussion on whether the premises provide good reasons for believing that the conclusion is correct. Note that until the characters in the video clip actually use the scale, they don't know whether some of the facts asserted in the premises are true. That's often the case in exploring philosophical questions. What's important is the logical relationship between the premises and the conclusion. Hypothetically, if the premises were all to turn out to be true, would they then make it likely that the conclusion would also be true? By asking that question, we can evaluate the reasoning in an argument. Philosophers often focus the most on this step. If the reasoning in an argument is good, then we can go on to ask whether the premises are in fact true. Often that requires empirical investigation (and so may require the aid of scientists or other specialists). If both are the case—the reasoning is good and the premises are true—only then should we assent to the conclusion.

After a few minutes, pause the discussion. Ask the students to write a paragraph defending why they are or are not convinced by the argument in the video clip. Remind everyone that the paragraph should, of course, take the form of an argument!