Guide for the Perplexed, Part 1, Introduction

Sixth cause: The contradiction is not apparent, and only becomes evident through a series of premises. The larger the number of premises necessary to prove the contradiction between the two conclusions, the greater is the chance that it will escape detection, and that the author will not perceive his own inconsistency. Only when from each conclusion, by means of suitable premises, an inference is made, and from the enunciation thus inferred, by means of proper arguments, other conclusions are formed, and after that process has been repeated many times, then it becomes clear that the original conclusions are contradictories or contraries. Even able writers are liable to overlook such inconsistencies. If, however, the contradiction between the original statements can at once be discovered, and the author, while writing the second, does not think of the first, he evinces a greater deficiency, and his words deserve no notice whatever.