Whether a natural disposition is requisite for prophecy?

Objections

Objection 1 : It would seem that a natural disposition is requisite for prophecy. For prophecy is received by the prophet according to the disposition of the recipient, since a gloss of Jerome on Amos 1:2, "The Lord will roar from Sion," says: "Anyone who wishes to make a comparison naturally turns to those things of which he has experience, and among which his life is spent. For example, sailors compare their enemies to the winds, and their losses to a shipwreck. In like manner Amos, who was a shepherd, likens the fear of God to that which is inspired by the lion's roar." Now that which is received by a thing according to the mode of the recipient requires a natural disposition. Therefore prophecy requires a natural disposition.
Objection 2 : Further, the considerations of prophecy are more lofty than those of acquired science. Now natural indisposition hinders the considerations of acquired science, since many are prevented by natural indisposition from succeeding to grasp the speculations of science. Much more therefore is a natural disposition requisite for the contemplation of prophecy.
Objection 3 : Further, natural indisposition is a much greater obstacle than an accidental impediment. Now the considerations of prophecy are hindered by an accidental occurrence. For Jerome says in his commentary on Matthew [*The quotation is from Origen, Hom. vi in Num.] that "at the time of the marriage act, the presence of the Holy Ghost will not be vouchsafed, even though it be a prophet that fulfils the duty of procreation." Much more therefore does a natural indisposition hinder prophecy; and thus it would seem that a good natural disposition is requisite for prophecy.