Sensing Absence
A Presently Pressing Perceptual Problem
Here, I want to put down some rough and speculative thoughts on an area of the philosophy of perception; namely, whether it is possible to sense absences, or metaphysical negatives.
In that subfield, we often speak of the “proper objects” of a sensory modality.1 A sensory modality is just a specific manner of sensing something. Vision is a sensory modality; it is a manner in which we perceive certain sensible objects. The same is true of audition (hearing), olfaction (smell), and so on. The proper objects of a sense are those things that only a specific sensory modality may take as an object.2
For example, traditionally, color was regarded as the proper object of vision. Plato and Aristotle are notable figures who endorsed the idea. In Plato’s Charmides, Socrates says this to Critias:
“And I take it the same goes for seeing, my good man: If it’s going to see itself, it will have to have some color; for seeing could never see anything colorless.” (168d-e)3
And in Aristotle’s De Anima II.7:
Whatever is visible is colour and colour is what lies upon what is in its own nature visible; ‘in its own nature’ here means not that visibility is involved in the definition of what thus underlies colour, but that that substratum contains in itself the cause of visibility. (418a25-30)4
Although it may appear as if color isn’t the only thing that vision takes as an object, one may claim that those things aren’t proper objects of vision. You might say that through vision, you may also ascertain shape, or contour, even if those properties are represented as a function of color. However, shape doesn’t appear to be specific to vision; I can ascertain the shape of an object through tactile sensation. When I rub my hand on a spherical surface, say a sphere of marble or granite, I can recognize that what I am feeling is a sphere. When I see that same object, I would also likely be disposed to identify its shape as spherical. Things like shape and contour are known as common sensibles; they are things that can be conveyed by two or more senses.
In audition specifically, the traditional proper object accorded to audition is sound. It seems like we can’t see sound, smell, taste, or touch sound; therefore, it appears as if sound is the proper object of audition. Though one may try to dispute this to an extent, our main concern is with a specific problem in the philosophy of audition, which may give rise to other problems in the philosophy of perception. Namely, whether only metaphysically positive qualities can be sensed, or whether or not metaphysically negative qualities can also be sensed.
When I talk about positive qualities, I mean qualities that are present to the perceiver in some way. For example, the fact that there is a cup on my table implies the presence of a cup on my table. However, the presence of the cup also makes other facts salient; a bottle of water is not on my table, nor a sticky note, nor the Eiffel Tower. Only the cup is. Those absences are negative qualities; things that aren’t present to the perceiver in the positive sense given above.
In the case of audition, this metaphysical difference is important since we appear to admit of the sensation of negative qualities intuitively! Ian Phillips in Hearing and Hallucinating Silence quotes this passage from Jack London’s White Fang:
White Fang trembled with fear, and though the impulse came to crawl out of his hiding place, he resisted it. After a time the voices died away, and sometime after that he crept out to enjoy the success of his undertaking. Darkness was coming on, and for a while he played about among the trees, pleasuring in his freedom. Then, and quite suddenly, he became aware of loneliness. He sat down to consider, listening to the silence of the forest and perturbed by it. (Italics mine)5
White Fang “listened” to the silence, despite the fact that by our earlier criteria, silence is a metaphysical absence. Silence is the absence of sound; where sound is present, silence is absent, and vice versa. How can it be that one can perceive something that is absent from the sense-organ altogether? It appears as if our apprehension of silence as if it were a presence doesn’t seem to be a peculiarity in our usage of the term, either. We often talk about “hearing” the silence around us, and doesn’t produce a contradiction, at least immediately, when we think of its possibility.
Phillips provides a justification for hearing silence through a perceptual framework developed by G.E. Moore.6 Put simply, Moore argued that the sensation of something involves two components: 1) The experience of the thing sensed (i.e. the subject’s relation to the thing perceived), and 2) The awareness of the sensation. In the case of silence, (1) is absent; silence is the absence of sound. There can’t be an experience of something if there’s nothing for the subject to stand in relation to. However, insofar as (2) still remains, it is possible that our awareness itself still remains. This standalone awareness, then, is what we refer to when we say that we “hear” silence; it is the awareness that results from the absence of a quality to stand in relation to us somehow.
If experience can entirely be analysed in terms of its objects, then where there is no object, there is no experience, merely an absence of such, ‘a mere emptiness’. In the auditory case: no sound, no experience. On the other hand, if we accept Moore‘s actual analysis, then where there is no object we might think that could be still be awareness itself. Thus, we can distinguish between true deafness and the experience of silence precisely by invoking the presence of conscious awareness.7
I wonder, though, if this argument is consistent across multiple sensory modalities. If we assume that the conclusion of Phillips’ Moorean argument is true across different modalities, then when we look at an empty table, we should “sense” the absence of a pen; the absence of a laptop; the absence of a cup of coffee; and so on. But we don’t seem to intuitively think that way. We would say that we perceive a decidedly positive quality, namely, an empty table. Even when we say that we “don’t see anything,” we are usually always still seeing something. By uttering that phrase, we usually mean “I don’t see the correct thing.” One could argue that you could plausibly see nothing if you’re blind; but your capacity to see has been removed altogether, making the possibility of seeing something, or the absence of something, essentially zero. Along similar lines, when we smell the scent of tea, we also aren’t disposed to say that we’re smelling the absence of smoke, dew, coffee, etc.
Even if Phillips is correct about his argument, it seems wildly strange from a metaphysical standpoint that somehow audition is the only sensory modality, at least justifiably, that can hear the absence of something. Even so, it’s not unheard of that some philosophers have tried to accord special statuses to specific sensory modalities. Olivier Massin and Frédérique de Vignemont have argued that touch, or tactile sensation, has an epistemic privilege when it comes to sensing the “reality” of objects; things seem to be tangible to a greater extent when we can feel our bodies resisting them.8 But Phillips seems to be making a more stark claim; an epistemic privilege is one thing, but including an absence as a proper object of a sense is quite another.
To me, it seems as if there are a couple of ways to respond to this view. One possible direction is to deny that we can hear silence, and repudiate the argument’s soundness in the first place. This would eliminate the metaphysical quandary, but let’s just assume that the conclusion is plausible and entertain it.
Another direction is a relational one. Maybe we do actually perceive absences in audition and other sensory modalities, but as a function of the relations we have between different objects of sense. We can only know that we see a cup on the table having already known that a cup has a certain set of features, and that other objects lack those features; in that sense, we may view our seeing the empty table as also seeing the implicit relations in our sensory arsenal. We know that the table is empty because we also know what tables are like when they are full of things. Still, this seems to skirt the crux of the problem. Do we actually sense the relations, or do we just implicitly let them structure our perceptual contents and judgments? We can’t take for granted that we already perceive the relations we have between objects, since it isn’t obvious that this is the case. Certainly, when I see an empty table, I can be aware that I know that the table is empty and not full; but being aware that I know about an absence isn’t equivalent to my apprehending the absence via my senses proper. This may also serve as an argument against the Moorean view generally; is awareness alone sufficient to count as properly “sensing” something?
Another, more compelling option (in my opinion) is to simply bite the bullet and say that, despite our initial inclinations and intuitions, we really are always sensing absences in every sensory modality. When we see a white wall, we really are also seeing not-red, not-blue, not-green, etc., and similarly when it comes to olfaction, touch, and taste. There tends to be a bias in Western philosophy that favors positive qualities over negative ones; and it may overlook the fact that the contents of our sensory experience don’t come neatly packaged as a set of positive qualities. Perhaps, in a Kantian sense, the “manifold” that we receive, or the initial unordered contents of experience, really are jumbles of positive and negative qualities that we then parse out in some kind of perceptual process. We only seem to perceive and refer to things in a positive sense out of convenience; we would sound crazy if we were to refer to our window as a set of all of its contraries. If someone asked me to open the window, I wouldn’t clarify by saying: “Oh, you mean the not-(Leaning Tower of Pisa)?” But logically speaking, my window really isn’t the Leaning Tower of Pisa, and in a sense I do perceive that fact. It’s just not the fact that is readily available to us when we receive the contents of our perception. Whether that’s the product of an implicit bias or a quirk of acquiring language, I don’t know.
Personally, I certainly think that we can apprehend absences in some way. Paraphrasing an example from Sartre, if I were to become accustomed to seeing my friend on campus at a specific location and time every day, and one day he isn’t there, in a way, I can feel his absence from my world. But, that apprehension seems different from actually sensing that absence. My apprehension of his absence may be the product of something other than my immediate response to a sense-organ provoked by a stimulus; maybe it’s the result of an intellectual process, or a perceptual yet higher-order process. Maybe I have to recognize the absence instead of sensing it. In any case, my opinions on this problem are fluid; there’s still much work and thinking to be done regarding whether we can truly sense absence.
I am indebted to one of my colleagues who wrote an essay on this topic, which inspired me to organize my own thoughts on it.
This literature puts aside special cases, such as synesthesia. There’s a literature dedicated to parsing out extraneous cases such as those. For a first pass, take a look at the IEP entry here, and for the more philosophically acquainted, the PhilPapers tag on synesthesia.
Plato (2019). Charmides. Translated by C. Moore. and Translated by C. Raymond. Hackett Publishing. p. 25.
Aristotle, Reeve, C.D.C. and Mckeon, R. (2008). The Basic Works of Aristotle. Modern Library Classics. p. 567.
London, J. (1992). Call of the wild and White fang. London: Wordsworth Classics, p. 141.
Phillips, I. (2013). "Hearing and Hallucinating Silence". In: Hallucination: Philosophy and Psychology. Cambridge, MA: MIT Press. pp. 344-5.
Ibid., pp. 345-6.
Massin, O. and De Vignemont, F. (2020). “Unless I put my hand into his side, I will not believe”. The Epistemic Privilege of Touch. In: The Epistemology of non-visual Perception. New York, NY: Oxford University Press.