Objection 1. It would seem that the prophetic vision is always accompanied by abstraction from the senses. For it is written (Numbers 12:6): "If there be among you a prophet of the Lord, I will appear to him in a vision, or I will speak to him in a dream." Now a gloss says at the beginning of the Psalter, "a vision that takes place by dreams and apparitions consists of things which seem to be said or done." But when things seem to be said or done, which are neither said nor done, there is abstraction from the senses. Therefore prophecy is always accompanied by abstraction from the senses.
Objection 2. Further, when one power is very intent on its own operation, other powers are drawn away from theirs; thus men who are very intent on hearing something fail to see what takes place before them. Now in the prophetic vision the intellect is very much uplifted, and intent on its act. Therefore it seems that the prophetic vision is always accompanied by abstraction from the senses.
Objection 3. Further, the same thing cannot, at the same time, tend in opposite directions. Now in the prophetic vision the mind tends to the acceptance of things from above, and consequently it cannot at the same time tend to sensible objects. Therefore it would seem necessary for prophetic revelation to be always accompanied by abstraction from the senses.
Objection 4.On the contrary, It is written (1 Corinthians 14:32): "The spirits of the prophets are subject to the prophets." Now this were impossible if the prophet were not in possession of his faculties, but abstracted from his senses. Therefore it would seem that prophetic vision is not accompanied by abstraction from the senses.
I answer that, As stated in the foregoing Article, the prophetic revelation takes place in four ways: namely, by the infusion of an intelligible light, by the infusion of intelligible species, by impression or coordination of pictures in the imagination, and by the outward presentation of sensible images. Now it is evident that there is no abstraction from the senses, when something is presented to the prophet's mind by means of sensible species--whether these be divinely formed for this special purpose, as the bush shown to Moses (Exodus 3:2), and the writing shown to Daniel (Daniel 5)--or whether they be produced by other causes; yet so that they are ordained by Divine providence to be prophetically significant of something, as, for instance, the Church was signified by the ark of Noah.
Again, abstraction from the external senses is not rendered necessary when the prophet's mind is enlightened by an intellectual light, or impressed with intelligible species, since in us the perfect judgment of the intellect is effected by its turning to sensible objects, which are the first principles of our knowledge, as stated in I, 84, 6.
When, however, prophetic revelation is conveyed by images in the imagination, abstraction from the senses is necessary lest the things thus seen in imagination be taken for objects of external sensation. Yet this abstraction from the senses is sometimes complete, so that a man perceives nothing with his senses; and sometimes it is incomplete, so that he perceives something with his senses, yet does not fully discern the things he perceives outwardly from those he sees in imagination. Hence Augustine says (Gen. ad lit. xii, 12): "Those images of bodies which are formed in the soul are seen just as bodily things themselves are seen by the body, so that we see with our eyes one who is present, and at the same time we see with the soul one who is absent, as though we saw him with our eyes."
Yet this abstraction from the senses takes place in the prophets without subverting the order of nature, as is the case with those who are possessed or out of their senses; but is due to some well-ordered cause. This cause may be natural--for instance, sleep--or spiritual--for instance, the intenseness of the prophets' contemplation; thus we read of Peter (Acts 10:9) that while he was praying in the supper-room [Vulgate: 'the house-top' or 'upper-chamber'] "he fell into an ecstasy"--or he may be carried away by the Divine power, according to the saying of Ezekiel 1:3: "The hand of the Lord was upon him."
Reply to Objection 1. The passage quoted refers to prophets in whom imaginary pictures were formed or coordinated, either while asleep, which is denoted by the word "dream," or while awake, which is signified by the word "vision."
Reply to Objection 2. When the mind is intent, in its act, upon distant things which are far removed from the senses, the intensity of its application leads to abstraction from the senses; but when it is intent, in its act, upon the coordination of or judgment concerning objects of sense, there is no need for abstraction from the senses.
Reply to Objection 3. The movement of the prophetic mind results not from its own power, but from a power acting on it from above. Hence there is no abstraction from the senses when the prophet's mind is led to judge or coordinate matters relating to objects of sense, but only when the mind is raised to the contemplation of certain more lofty things.
Reply to Objection 4. The spirit of the prophets is said to be subject to the prophets as regards the prophetic utterances to which the Apostle refers in the words quoted; because, to wit, the prophets in declaring what they have seen speak their own mind, and are not thrown off their mental balance, like persons who are possessed, as Priscilla and Montanus maintained. But as regards the prophetic revelation itself, it would be more correct to say that the prophets are subject to the. spirit of prophecy, i.e. to the prophetic gift.
Source: Summa Theologica (New Advent)