Can you explain Brie Gertler’s disembodiment argument to me?
Answer by Jürgen Lawrenz
Probably the best way to approach this argument is via psychosomatic pain, where it is often uncertain whether such pain is ‘imaginary’ or a real pain caused by the sympathetic reaction of some somatic processes. One doesn’t have to be a medico to understand that emotional turmoil can affect our organs. Gertler’s argument therefore centres on the age-old dilemma of how mental states can physically affect the body.
It insinuates the existence of two radically different communications pipelines (or forms of energy) in the body. But although electrochemical signalling is measurable on suitably calibrated instruments, the flow of energy being rendered visible as scintillations can only be distinguished from others by the site where they occur. In other words, the excitation of a nerve that carries a pain signal from a cut to the brain does not wear the label ‘pain’; we deduce from the fact that the signal is transported from this place to a particular sector of the brain that the recipient must be feeling ‘pain’. Therefore Gertler’s first line of attack is on the common viewpoint that the excitation of a nerve strand and the feeling of pain are two aspects of one experience, which can be understood as identical with each other.
But Gertler objects that this is confusing a physical signal with a non-physical mental or emotional state. Evidently ‘physical’ means embodied, whereas ‘non-physical’ means disembodied. As it happens, the notion of identity is based on a (deliberate?) forgetfulness that it isn’t the brain which suffers, but rather that it acts as a ‘go between’, converting the sensory excitation into a sense of pain and piping it into the person’s consciousness. The upshot is an inescapable logic asking for an autonomous, yet disembodied recipient faculty that is not in receipt of an unmediated communication from a throbbing nerve.
All the above has repercussions on matters of the mind such as ideas, thoughts, concepts, imagination etc. Gertler has no compunction defending Descartes’ dual substance doctrine, i.e. that he was right in his fundamental distinction between res extensa (embodied matter) and res cogitans (disembodied faculty aka mind). This does not entail having to defend Descartes’ gross errors when it comes to details, of which no-one takes notice any more. Even so, there are all sorts of other issues entangled in this duality from which Gertler’s approach could draw the sting.
Consider the reports of persons who had a leg amputated, but insist that they can still wriggle their toes. The ‘disembodiment’ idea can guide us towards a feasible resolution. It may be a memory pipeline that wasn’t closed, so that the impulse for toe wriggling (which is of course disembodied) remains alive in the brain; and as the brain ‘expects’ a wriggling response, it conveys it as a ‘fact’ to your mind, even though it is now physically impossible. We don’t know this, of course, but is a plausible scenario.
Consider further the effect of anaesthesia. Here the problem to overcome is the habit of neural afferents to ‘switch off’ when a signal is detected as a steady pulse; and they remain in the ‘off’ position until the sensation changes in nature or strength. The corollary to this is that the brain keeps the impression of pain alive until a new instruction arrives. In other words: The circuit from afferent to the brain is actually broken for a considerable length of time, even while brain continues ‘manufacturing’ a feeling of pain. The application of an analgesic is then equivalent to ‘news’ for the brain to react by ‘switching off’ the pain. It is hard to conceive of a more persuasive scenario for the plausibility of Gertler’s ‘disembodiment’ theme.
One more issue raised by Gertler points in the same direction. She says, I can easily conceive of a pain at any time, without actually feeling it. This reflects our imaginative capacity as well as our ability to conceptualise experiences and then ‘play’ them through the mind — in retrospect, in envisioning a future, even in fiction. It summarily rebuts the notion that sensory stimulation and its effect on our consciousness comprise an unfiltered unity. Concepts are disembodied too!
In sum: Gertler’s ‘disembodiment argument’ seeks to redress a lopsided scientific position which has been overstressing the physicalist position for so long by now, that it seems part of the furniture. If I may speak pro domo for a moment, it has always seemed incomprehensible to me that the scientific enterprise of our civilisation painted itself into a corner from which there is no exit except to disown the idea of a disembodied substance — as if the universe is not rich enough to engender two substances and for objects imbued with life to avail themselves of both!