Error In Reasoning
Correct facts can lead to wrong conclusions if reasoning is flawed, as with Ptolemy’s earth theory.
It frequently happens that men are perfectly correct in their premises and in observing the facts, while their conclusions may be wholly wrong.
Ptolemy clearly saw that, if the alternation from day to night is caused by a rotation of the earth, then points on the equator must move with a speed of nearly one thousand miles an hour, a velocity exceeding more than tenfold that of the wind in the severest storm. A terrible gale would thus always blow from the east; birds in flight and objects thrown into the air would be left behind and carried with frightful rapidity toward the west. As these things do not happen, the earth, Ptolemy concludes, must be at rest.--CHARLES LANE POOR, “The Solar System.”