Thomas Cole, Angels Ministering to Christ in the Wilderness, 1843
A short bio of Mort Adler is at the beginning of this post here.
One reason for affirming the possibility of angels has already emerged. The fact that materialism — the philosophical doctrine most antagonistic to the notion of spiritual beings — provides no grounds for denying the possibility of such beings is a negative approach to affirming their possibility. To acknowledge that we have no reason for thinking angels impossible is tantamount to conceding that they are possible. Can we go beyond this and find positive reasons for an affirmative conclusion?
St. Thomas Aquinas pointed out that the failure to acknowledge the possibility of spiritual beings stems from the failure to distinguish between sense-perception and imagination, on the one hand, and intellection or understanding, on the other. This failure led some philosophers to the conclusion that nothing exists or can exist except that which can be sensed and imagined. Since nothing is perceptible or imaginable other than bodies, these philosophers concluded that only bodies exist or can exist.
Both Plato and Aristotle, Aquinas observed, corrected this error on the part of earlier philosophers. They both recognized a realm of intelligible objects — objects of thought, quite distinct and separate from a realm of sensible objects — objects of perception and imagination. Corresponding to that distinction, they recognize that man has two distinct powers of apprehending objects: on the one hand, the sensitive powers that man shares with other animals; on the other hand, the intellectual powers that only human beings possess.
Intelligible objects or objects of thought are not apprehended as bodies or as having bodily attributes. On the contrary, they are apprehended devoid of all corporeal or material characteristics. That such immaterial objects exist as objects of thought does not lead to the conclusion that they also exist in reality, quite apart from human thought, but it does at least permit us to affirm the possibility of their existence.
A second reason advanced by Aquinas for thinking that minds without bodies are possible is the view he held concerning the human intellect and its action. Adopting Aristotle’s analysis of man’s powers, Aquinas maintained that all but one of these are corporeal powers, the actions of which are the actions of bodily organs.
According to this view, digestion is the act of the organs of the alimentary system; locomotion, the act of the skeletal and muscular systems; sensing, the act of the sense organs and brain; imagining, the act of the brain when the senses are not in operation. But intellection — understanding and thinking — is not correspondingly the act of the brain. It is the act of an incorporeal power that man possesses.
Neither Aristotle nor Aquinas supposed that we can understand or think without that activity being accompanied by the activity of the brain. They both recognized the effect upon our power to think of brain injuries, of drugs, and of the fatigue poisons that cause sleep. However, to admit that we cannot think or understand without using the brain is not to say that we think or understand simply by using the corporeal organ that is primarily an organ of sense-perception, sensory imagination, and sensory memory.
The moderate materialist, as we have seen, regards brain action as both a necessary and a sufficient condition for all mental processes, whether these are sensory or intellectual; but he does not identify mental processes with the processes of the brain and nervous system. He recognizes that they are distinguishable. Each has properties not possessed by the other.
It would, therefore, appear quite appropriate to call Aristotle and Aquinas moderate immaterialists. They do not go to the extreme of asserting that a mind that is associated with a human body has the power to think and understand in and of itself, without dependence on any bodily organ. In contrast to such extreme immaterialism, their view is that the action of the brain and nervous system is a necessary, but not a sufficient, condition for understanding and thinking. The action of the human intellect — in their view, an incorporeal power, a power not seated in a bodily organ — is required for understanding or thinking to occur.
Here, then, we have another argument for the possibility of minds without bodies — intellects not associated with bodies as the human intellect is. Affirming man’s possession of an intellect that is an incorporeal power, moderate immaterialists, such as Aristotle and Aquinas, see no obstacle whatsoever to affirming the possibility of intellects superior to the human intellect, superior precisely because they are totally divorced from bodies.
There is still a fourth view to consider — that of the seventeenth-century French philosopher, Descartes. His theory of the human mind is that it is, in and of itself, a thinking substance — a res cogitans. It is associated with the human body, which is an utterly different kind of substance, a res extensa or extended substance, having the tri-dimensionality of physical bulk.
Let us ignore for the moment all the well-nigh insoluble difficulties of the so-called “mind-body problem” that arise from the association in one individual of two such disparate substances. I will return to them later. Here we need only note two things.
The first is that the Cartesian view completes the picture by being the extreme immaterialism that lies at the other end of the line from the extreme materialism that totally identifies mental with physical processes. In between these two extremes are the two moderate views that I have described as moderate materialism and moderate immaterialism.
The second point is what follows from the Cartesian affirmation of the existence in the human individual of an intellect that is a thinking substance, not only distinct from, but also separate in its existence and operation from, the extended substance that is the human body. Holding that to be the case, the Cartesian doctrine does not hesitate to embrace the possibility of there being minds totally divorced from bodies.
In fact, on the Cartesian view, the existence of such completely separated thinking substances is less difficult to understand than the existence of the human mind that, while separate in its existence from a body, is nevertheless associated with one — inexplicably.
In one of the Objections and Replies attached to his Meditations, Descartes tells us that from the ideas we possess of God and of man, especially our idea of the human intellect as a thinking substance, we have no difficulty whatsoever in forming the ideas of angels as pure intelligences — thinking substances not in any way associated with bodies, as human intellects are. Certainly, any philosopher who, on rational grounds, affirms the real existence of God can affirm, not the actual existence of angels, but the possibility of their existing. One qualification must be added to the foregoing statement; namely, that the God whose existence is affirmed must be understood to be not only the supreme being, uncaused and unconditioned, but also a purely spiritual and infinite being.
Even to ask the question whether such a being really exists presupposes the acknowledgment of the possibility of its existence. As much as the theist who affirms, the atheist who denies makes this acknowledgement. Atheism, in all its forms, does not deny the possibility, but only the actuality of God.
So, too, the agnostic denies only the knowability of God — our being able to know by reason God’s existence or attributes. The agnostic does not deny that God is thinkable by us — that we can form the notion of a purely spiritual being, having an existence that is independent of the existence of anything else.
If the possibility of there being a God, or of our being able to ask whether or not God exists, rests on our being able to think of God without self-contradiction, then, a fortiori, the same reasoning applies to angels — purely spiritual beings that are finite rather than infinite. Unlike God, if these finite spiritual beings do really exist, they exist dependently, not independently. Their existence depends upon their being created by God and sustained in existence by God.
A metaphysical insight underlies all the arguments advanced so far in support of the affirmation that God and angels are at least possible beings. It has two ingredients.
One is the conception of a substance as anything having an existence separate from the existence of everything else, even though its existence may interact with or be related to the existence of other things. An atom, a stone, a tree, a horse, a human being — each is a substance in this sense of the term. The atom’s weight, the stone’s shape, the tree’s height, the horse’s color, and the human being’s talents are not substances. They are attributes of the substances to which they belong. They do not have any existence separate from the existence of the substance of which they are attributes.
The second element involved in the underlying metaphysical insight is the recognition that the various physical dimensions or properties that comprise the characteristics of corporeal substances are accidental rather than essential attributes of substance itself.
This is tantamount to saying that while this or that physical attribute may be necessarily present as a property of corporeal substances, it is not necessarily present in all substances. The notion of substance does not necessarily involve the possession of such attributes.
Therefore, it follows that incorporeal substances, such as angels or minds without bodies, can exist without having the physical attributes possessed by corporeal substances.
To see that this is so is to see that purely spiritual substances — God, angels, or minds without bodies — are possible modes of being.
There remains only to add the contribution made by John Locke to the discussion of this subject. In his Essay Concerning Human Understanding, he dwells at length and in many places on the comparable intelligibility of corporeal and incorporeal substances. He is at pains to point out all the difficulties that confront us in dealing with the notion of substance as that underlying substratum in which attributes inhere. But our difficulties, he declares, are no greater in the case of spirits, or incorporeal substances, than in the case of bodies, or corporeal substances.
The fact that the attributes of bodies are perceptible by our senses, whereas the attributes of spirits are not, does not make spiritual substances any less intelligible to us than corporeal substances. The fact that we can know the existence of corporeal substances directly by sense-perception, whereas we have no such immediate knowledge of the existence of spiritual substances, does not affect either the intelligibility or the possibility of the latter. The possibility of angels, or minds without bodies, being thus explained as something we need not hesitate to affirm, philosophy is called upon to explore that possibility. Granted that angels are possible beings, what more can be said about them by the philosopher proceeding, as he should, without any light drawn from Divine revelation or from articles of religious faith?