The objections raised to a creatio ex nihilo by its opponents are founded partly on the properties of Nature, and partly on those of the Primal Cause. They infer from the properties of Nature the following arguments: (1) The first moving force is eternal; for if it had a beginning, another motion must have produced it, and then it would not be the First moving force. (2) If the formless matter be not eternal, it must have been produced out of another substance; it would then have a certain form by which it might be distinguished from the primary substance, and then it would not be formless. (3) The circular motion of the spheres does not involve the necessity of termination; and anything that is without an end, must be without a beginning. (4) Anything brought to existence existed previously in potentia; something must therefore have pre-existed of which potential existence could be predicated. Some support for the theory of the eternity of the heavens has been derived from the general belief in the eternity of the heavens.—The properties of the Primal Cause furnished the following arguments:—If it were assumed that the Universe was created from nothing, it would imply that the First Cause had changed from the condition of a potential Creator to that of an actual Creator, or that His will had undergone a change, or that He must be imperfect, because He produced a perishable work, or that He had been inactive during a certain period. All these contingencies would be contrary to a true conception of the First Cause (ch. xiv.). Maimonides is of opinion that the arguments based on the properties of things in Nature are inadmissible, because the laws by which the Universe is regulated need not have been in force before the Universe was in existence. This refutation is styled by our author “a strong wall built round the Law, able to resist all attacks” (ch. xvii.). In a similar manner the author proceeds against the objections founded on the properties of the First Cause. Purely intellectual beings, he says, are not subject to the same laws as material bodies; that which necessitates a change in the latter or in the will of man need not produce a change in immaterial beings. As to the belief that the heavens are inhabited by angels and deities, it has not its origin in the real existence of these supernatural beings; it was suggested to man by meditation on the apparent grandeur of heavenly phenomena (ch. xviii.).