causal relation to each other. This causal relation is the essential order of nature, in which, as has been fully proved, the infinite is impossible. As regards the virtual and the accidental existence of the infinite, it has been established in some cases; it has been proved, e.g., that a body can virtually be divided ad infinitum, also that time can be divided ad infinitum; in other cases it is still an open question, as, e.g., the existence of the infinite in succession, which is called the accidental infinite, i.e., a series of things in which one thing comes forth when the other is gone, and this again in its turn succeeded a thing which had ceased to exist, and so on ad infinitum. This subject requires deep research.
Those who boast that they have proved the eternity of the Universe say that time is infinite; an assertion which is not necessarily erroneous; for only when one atom has ceased to exist, the other follows. Nor is it absolutely wrong, when they assert, that the accidents of the substance succeed each other in an infinite series, for these accidents do not co-exist, but come in succession one after the other, and the impossibility of the infinite in that case has not been proved. The Mutakallemim, however, make no difference between the existence of an infinite body and the divisibility of a body or of time ad infinitum, between the co-existence of an infinite number of things, as e.g., the individual human beings who exist at present, and the infinite number of beings successively existing, as, e.g., Reuben the son of Jacob, and Jacob the son of Isaac, and Isaac the son of Abraham, and so on to infinity. This is according to their opinion as inadmissible as the first case; they believe these four forms of the infinite to be quite equal. Some of the Mutakallemim endeavour to establish their proposition concerning the last named form of the infinite, and to demonstrate its impossibility by a method which I shall explain in this treatise; others say that this impossibility is a self-evident axiom and requires no further proof. But if it were undoubtedly wrong to assume that an infinite number of things can exist in succession, although that link of the series which exists at present is finite, the inadmissibility of the eternity of the Universe would be equally self-evident, and would not require for its proof any other proposition. This, however, is not the place for investigating the subject.
TWELFTH PROPOSITION.
"The senses are not always to be trusted." For two reasons the Mutakallemim find fault with the perception of the senses. First, the senses are precluded from perceiving many objects, either on account of the smallness of the objects--this is the case with the atoms, as we have already stated--or on account of the remoteness of the objects from the person who desires to perceive them; e.g., we cannot see, hear, or smell at a distance of many miles; nor do we perceive the motion of the heavens. Secondly, the senses misapprehend the objects of their perception: a large object appears small from a distance; a small object immersed in water appears larger; a crooked thing appears straight when partly placed in water, and partly out of it; things appear yellow to a person suffering from jaundice; sweet things are bitter to him whose tongue has imbibed red gall; and they mention many other things of this kind. Therefore they say, we cannot trust our senses so far as to establish any proof on their perceptions. You must not believe that
