"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.[1]
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”)[2]
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.
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