"Why don't they teach logic at these schools?"
“Logic!” said the Professor half to himself.
“Why don’t they teach logic at these schools?”
- C. S. Lewis, The Lion, the Witch and the Wardrobe -
I recently came across this picture, which seems to be making the rounds on social media in one form or another. What do you suppose is its purpose, its intended meaning? What conclusion does its creator wish us to draw? Is it simply that blacks, whites, gays, straights, religious people, and atheists all have the same basic skeletal structure? This is true enough, of course, but also so obvious as to scarcely need pointing out.
So what is its meaning? Given the social and political climate of the day, it seems to be this: that blacks, whites, gays, straights, religious people, and atheists are all morally equivalent. The picture contains an argument that might be expressed in the following syllogism:
People who have the same skeletal structure are morally equivalent.
Blacks, whites, gays, straights, religious people, and atheists have the same skeletal structure.
Therefore, blacks, whites, gays, straights, religious people, and atheists are morally equivalent.
So what are we to think of the logical value of this argument? Is it valid? That is, does the conclusion follow from the premises? Yes. If it is true that people with the same skeletal structure are morally equivalent; and if it is true that blacks, whites, gays, straights, religious people, and atheists have the same skeletal structure, then it is necessarily true that such people are morally equivalent.
However, while the argument is valid, it is not sound. Let us pause for a moment and remind ourselves of the difference between validity and soundness. A valid argument is one in which the conclusion necessarily follows from the premises, regardless of whether or not the premises are true. Consider an example:
All men have beards.
Doug Enick is a man.
Therefore, Doug Enick has a beard.
This argument is valid (the conclusion—which also happens to be true—necessarily follows from the premises), but it is not sound because one of the premises (the first) is false. Soundness is stronger than validity. To say an argument is valid is to say that its conclusion follows from its premises. To say that an argument is sound is to say not only that its conclusion follows from its premises, but also that its premises are true.
The argument implied in the picture above, though valid, is not sound because the first premise (“People who have the same skeletal structure are morally equivalent”) is false. What does skeletal structure have to do with morality? This point might become clearer if we add a couple skeletons to the picture. Label one, Hitler, and the other, Mother Theresa. They have the same basic skeletal structure. Shall we therefore conclude they are morally equivalent?
We should further observe that the minor term (“blacks, whites, gays, straights, religious people, and atheists”) compares apples and oranges. The color of one’s skin is an immutable physical characteristic and has no moral bearing. Sexual behavior, on the other hand, is…well, behavior, and as such has moral implications. The same can be said with respect to acknowledging or refusing to acknowledge God (religious people and atheists).
The implied argument, then, clearly fails. The most the picture “proves” is that all people, regardless of skin color, sexual behavior, or religious viewpoint, have the same skeletal structure. But then again we already knew that.