sbccPhil-111 Critical Thinking and Writing:

Analogical Reasoning, Argumentation and Refutation





As popular as it is problematic, arguments from analogy are powerful tools in the hands of skilled individuals in the task of persuasion. And like casual arguments they have significant defects and limitations that need careful study by critical thinkers.

As noted previously, analogical arguments, are those observing that since two or more things or events are alike in some way that they are probably alike in some other way. These forms of argumentation have two principle functions, rhetoric and refutation. Rhetoric, it will be recalled is the art of persuasive communication. Refutation is the art of critical thinking raised to the highest level.

First, throughout the history of ideas, persuasive arguments from analogy have been used whenever direct empirical evidence is unavailable either in principle or in practice. The example argument given before, comparing the need to postulate a watchmaker from the appearance of a watch with the need to postulate an intelligent ‘maker’ of the Universe itself has historical resonance. This analogical argument presents as reasonable the notion that since complicated watches need a watchmaker to explain their existence, then so too a complicated Universe needs an intelligent maker in order to explain its existence. On first reading this argument from analogy seems perfectly reasonable. However, just a few questions raised by a critical thinker reveals that the reasonableness of this argument is highly suspect.

Second, arguments from analogy have historically served as the most artistically skillful way to refute other arguments. Indeed, from Galileo’s famous refutation of the Catholic Church’s view that the moon is a perfectly smooth sphere through Gaunilo’s classic refutation of Anselm’s Ontological Proof for the existence of God, refutation by analogy is alive an well as practiced by trial attorney’s around the globe defending their petitions at court. Aristotle, as quoted in the Refutation class notes, was of the view that refutation by analogy was the highest level of human intelligence. He sufficiently describes how the art of refutation proceeds:

"An argument may be refuted either by a counter-syllogism or by bringing an objection. It is clear that counter-syllogisms can be built up from the same lines of arguments as the original syllogisms: for the materials of syllogisms are the ordinary opinions of men, and such opinions often contradict each other. Objections, as appears in the Topics, may be raised in four ways -- either by directly attacking your opponent's own statement, or by putting forward another statement like it, or by putting forward a statement contrary to it, or by quoting previous decisions," (Aristotle's Rhetoric, Book 2, Chapter 25).

The reasoning pattern of all arguments from analogy looks something like this:

Analogically Correct Form
1. A is F and G
2. B is F
Conclusion: B is G.

1. Whales and dolphins are marine animals that give live birth and nourish their young with milk, and they're mammals.
2. Manatees are marine animals that give live birth and nourish their young with milk.
Conclusion: Manatees are mammals.

Here are some classic examples from the history of philosophy.


“Tell me: does this also apply to horses, do you think? That all men improve them and one individual corrupts them? Or is quite the contrary true, one individual is able to improve them, or very few, namely, the horse breeders, whereas the majority, if they have horses and use them, corrupt them? Is that not the case, Meletus, both with horses and all other animals? Of course it is, whether you and Anytus say so or not. It would be a very happy state of affairs if only one person corrupted our youth, while the other improved them.” (Apology 25b).

Thomas Aquinas:

“We see that things which lack knowledge, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that they achieve their end, not fortuitously, but designedly. Now whatever lacks knowledge cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is directed by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God” (Aquinas, Article 3, Question 2).

Immanuel Kant:

Morality is a rational enterprise.

Morality would not be a rational enterprise if there were no moral order in the world.

Only the existence of God traditionally conceived could support the hypothesis that there is a moral order in the world.

Therefore, there is a God.

By far the most impressive use of analogy in the history of philosophy is Plato’s Allegory of The Cave. An allegory is an extended analogy. Here, in complete form is Plato’s argument from analogy on the levels of human knowledge. Enjoy as millions before you have. Read it to your children.

Is a resident of the cave (a prisoner, as it were) likely to want to make the ascent to the outer world? Why or why not? What does the sun symbolize in the allegory? And now, I said, let me show in a figure how far our nature is enlightened or unenlightened:--Behold! human beings living in an underground den, which has a mouth open towards the light and reaching all along the den; here they have been from their childhood, and have their legs and necks chained so that they cannot move, and can only see before them, being prevented by the chains from turning round their heads. Above and behind them a fire is blazing at a distance, and between the fire and the prisoners there is a raised way; and you will see, if you look, a low wall built along the way, like the screen which marionette players have in front of them, over which they show the puppets.

I see.

And do you see, I said, men passing along the wall carrying all sorts of vessels, and statues and figures of animals made of wood and stone and various materials, which appear over the wall? Some of them are talking, others silent.

You have shown me a strange image, and they are strange prisoners.

Like ourselves, I replied; and they see only their own shadows, or the shadows of one another, which the fire throws on the opposite wall of the cave?

True, he said; how could they see anything but the shadows if they were never allowed to move their heads?

And of the objects which are being carried in like manner they would only see the shadows?

Yes, he said.

And if they were able to converse with one another, would they not suppose that they were naming what was actually before them?

Very true.

And suppose further that the prison had an echo which came from the other side, would they not be sure to fancy when one of the passers-by spoke that the voice which they heard came from the passing shadow?

No question, he replied.

To them, I said, the truth would be literally nothing but the shadows of the images.

That is certain.

And now look again, and see what will naturally follow if the prisoners are released and disabused of their error. At first, when any of them is liberated and compelled suddenly to stand up and turn his neck round and walk and look towards the light, he will suffer sharp pains; the glare will distress him, and he will be unable to see the realities of which in his former state he had seen the shadows; and then conceive some one saying to him, that what he saw before was an illusion, but that now, when he is approaching nearer to being and his eye is turned towards more real existence, he has a clearer vision,--what will be his reply? And you may further imagine that his instructor is pointing to the objects as they pass and requiring him to name them,--will he not be perplexed? Will he not fancy that the shadows which he formerly saw are truer than the objects which are now shown to him?

Far truer.

And if he is compelled to look straight at the light, will he not have a pain in his eyes which will make him turn away to take refuge in the objects of vision which he can see, and which he will conceive to be in reality clearer than the things which are now being shown to him?

True, he said.

And suppose once more, that he is reluctantly dragged up a steep and rugged ascent, and held fast until he is forced into the presence of the sun himself, is he not likely to be pained and irritated? When he approaches the light his eyes will be dazzled, and he will not be able to see anything at all of what are now called realities.

Not all in a moment, he said.

He will require to grow accustomed to the sight of the upper world. And first he will see the shadows best, next the reflections of men and other objects in the water, and then the objects themselves; then he will gaze upon the light of the moon and the stars and the spangled heaven; and he will see the sky and the stars by night better than the sun or the light of the sun by day?


Last of all he will be able to see the sun, and not mere reflections of him in the water, but he will see him in his own proper place, and not in another; and he will contemplate him as he is.


He will then proceed to argue that this is he who gives the season and the years, and is the guardian of all that is in the visible world, and in a certain way the cause of all things which he and his fellows have been accustomed to behold?

Clearly, he said, he would first see the sun and then reason about him.

And when he remembered his old habitation, and the wisdom of the den and his fellow-prisoners, do you not suppose that he would felicitate himself on the change, and pity them?

Certainly, he would.

And if they were in the habit of conferring honors among themselves on those who were quickest to observe the passing shadows and to remark which of them went before, and which followed after, and which were together; and who were therefore best able to draw conclusions as to the future, do you think that he would care for such honors and glories, or envy the possessors of them? Would he not say with Homer

Better to be the poor servant of a poor master, and to endure anything, rather than think as they do and live after their manner? (1)

Yes, he said, I think that he would rather suffer anything than entertain these false notions and live in this miserable manner.

Imagine once more, I said, such a one coming suddenly out of the sun to be replaced in his old situation; would he not be certain to have his eyes full of darkness?

To be sure, he said.

And if there were a contest, and he had to compete in measuring the shadows with the prisoners who had never moved out of the den, while his sight was still weak, and before his eyes had become steady (and the time which would be needed to acquire this new habit of sight might be very considerable), would he not be ridiculous? Men would say of him that up he went and down he came without his eyes; (2) and that it was better not even to think of ascending; and if any one tried to loose another and lead him up to the light, let them only catch the offender, and they would put him to death. (3)

No question, he said.

This entire allegory, I said, you may now append, dear Glaucon, to the previous argument; the prison-house is the world of sight, the light of the fire is the sun, and you will not misapprehend me if you interpret the journey upwards to be the ascent of the soul into the intellectual world according to my poor belief, which, at your desire, I have expressed--whether rightly or wrongly God knows. But whether true or false, my opinion is that in the world of knowledge the idea of good appears last of all, and is seen only with an effort; and, when seen, is also inferred to be the universal author of all things beautiful and right, parent of light and of the lord of light in this visible world, Here Plato describes his notion of God in a way that was influence profoundly Christian theologians and the immediate source of reason and truth in the intellectual; and that this is the power upon which he would act rationally either in public or private life must have his eye fixed.

I agree, he said, as far as I am able to understand you.

[Translated by Benjamin Jowett]


(1) This refers to a famous passage in Homer's Odyssey in which the ghost of the great hero Achilles, when asked if he is not proud of the fame his deeds has spread throughout the world, answers that he would rather be a slave on a worn-out farm than king over all of the famous dead. Interestingly, Plato quotes the same passage elsewhere as disapprovingly as depicting life after death in such a negative manner that it may undermine the willingness of soldiers to die in war.

(2) The comic playwright Aristophanes had mocked Socrates by portraying Plato's master, Socrates, as a foolish intellectual with his head in the clouds.

(3) Plato undoubtedly has in mind the fact that the Athenians had condemned to death his master Socrates, who Plato considered supremely enlightened.