Chapter 92 <There are no people, no flowers, no trees on that side of the earth>

There were formerly those who denied the existence of antipodes (i.e. people who inhabited the positive and negative sides of the earth), and they argued thus: On the other side of the earth, there are no people, flowers, trees, rain, snow and hail.Is there really such a lunatic who would believe that there are people who walk with their heads upside down and their feet upside down, that flowers, grass and trees grow from the top down, and that rain, snow and hailstones fall from the bottom up. The above argument is a method of proof by application of logic, that is, to prove that the thesis contradicting the thesis to be proved is false first, and then deduce that the thesis to be proved is true according to the law of excluded middle.Here, the topic to be proved is that there are no people, flowers, trees, rain, snow and hail on the side of the earth, and its contradictory topic is that there are people, flowers, trees, rain, snow and hail on the side of the earth.

In proving that this contradictory thesis is false, reductio absurdum is applied.That is to say, the contradictory thesis of the topic to be proved is taken as the antecedent of the sufficient condition hypothesis judgment, and the latter is deduced from it: people on the other side of the earth walk with their heads down and their feet up, flowers and trees grow from top to bottom, rain, snow and hail grow from top to bottom. Since the latter is absurd, the former can be directly negated, thus indirectly affirming the topic to be proved (applying the law of excluded middle). However, the argument of this reductio absurdum is incorrect, because the hypothetical judgment as a sufficient condition of the argument cannot be established, and the latter cannot be deduced from the antecedent.The reason why the arguer thinks that the latter can be deduced from the antecedent is because the two concepts of up and down are absolutized, and they cannot see the relationship of unity of opposites that is interdependent and mutually transformable between the two.In fact, for the positive and negative sides of the earth, the distinction between up and down is relative, and they are all relative to the center of the earth.All that moves away from the direction of the earth's center is upward, and all that moves toward the earth's center is downward.

According to this standard, the flowers, plants and trees living on both sides of the earth grow from the bottom to the top, and rain, snow and hail also fall from the top, and their situations are by no means the opposite; People who walk on the ground on both sides of the earth have their heads up and their feet down, and their situation is by no means the other way around.Therefore, the sophistical nature of the above-mentioned argument lies in the fact that the arguments it uses have committed what logic calls the error of making the relative absolute.