Porous Memory and the Cognitive Life of Things
John Sutton
Page 3
Source: http://www.phil.mq.edu.au/staff/jsutton/CognitiveLifeOfThings.htm
The Cartesian philosophy of the brain
Just at the time the story of the sponge was circulating in France, a little-known anatomist and proponent of the new mechanical philosophy was completing a strange book on the philosophy of the body. After an extensive programme of dissection in which he had opened "the heads of various animals [to] explain what imagination, memory, etc. consist in", Rene Descartes described the brain as "a rather dense or compact net or mesh", composed of ‘tissues’ or flexible filaments with "pores or intervals" between them (Descartes 1996, 1.263, 11.171) . Through these pores or conduits flow nervous fluids, the fleeting ‘animal spirits’, which "trace figures in these gaps", patterned traces which somehow represent remembered objects and events (1996, 11.178) .
These animal spirits, which are the medium of memory and the passions, are derived from blood . Their particular state – their agitation, abundance, and purity – depends on the balance of bodily fluids (blood, semen, spirits, humours, sweat, tears, milk, fat) in the individual’s internal environment; and this balance in turn depends on a ceaseless cosmobiological exchange of vapours between body and world (Descartes 1996, 11.167-70; compare Carter 1983). Descartes’ body-machines, animated statues that dream, imagine, feel, and remember (Descartes 1996, 11.120, 201-2), are embedded in the same fluid dynamics which drive the whirling vortices of Cartesian cosmology (Gaukroger 1995, 249-256; Sutton 1998, 82-90). The body, like the cosmos, is full, so that every motion is inevitably coupled with other motions, in a physics of circulation and displacement, which is quite unlike a system of isolated atoms colliding in a void.
Through the blood and animal spirits, as Descartes’ follower Malebranche (1980, 341-2) wrote, after the Fall we are all "to some extent joined to the entire universe", for each man is linked
through his body to his relatives, friends, city, prince, country, clothes, house, land, horse,
dog, to this entire earth, the sun, the stars, to all the heavens.
So the Cartesian body is not rigid and dull, its behaviour ‘automatic’ in the sense of endlessly repeatable. Rather, "with its interactive openness", it is the means by which difference is introduced into the human compound (Foti 1986, 76; compare Rorty 1992, Reiss 1996, Sutton 2000a). External parameters like diet, climate, social interactions, and stress, which change at a relatively slow rate, directly affect the fast dynamics of the internal state variables of blood and spirits. But because the spirits are the medium of perception, passion, memory, and imagination, and thus cause our behaviour, changes in those external parameters are themselves partly caused by the internal processes with which they are coupled (for the terminology compare van Gelder and Port 1995, 23-25).
Every act of remembering, then, as the reconstruction of patterns of flow in the animal spirits roiling through the pores of the brain, is context-dependent and causally holistic. Several different figures, Descartes notes, are usually "traced in [the] same region of the brain" (1996: 11.185), so that every recomposed memory pattern is composite, just as every sensation dangerously carries the perceptual history of the perceiver. A single "fold of the brain" can "supply" many of the things we remember: Descartes thus dismisses any worries about the problem of finding room in the brain for all our memories, as they are "stored" only superpositionally and implicitly (Descartes 1991, 143, 148; Sutton 1998, 57-66).
Misassociation and imagination are thus intrinsic to the fluid dynamics of the Cartesian brain. Order is not built in to memory. Descartes hoped nevertheless to enforce clear distinctions between memory and imagination externally, by recourse to the guidance of reason. But few contemporaries found this at all plausible, and Descartes’ theory of memory was thus one of the most fiercely criticized strands of his natural philosophy in the second half of the 17th century. English natural philosophers in particular complained that Descartes couldn’t guarantee personal control over the preservation of the personal past. On Descartes’ view of memories as motions, argued Joseph Glanvill, remembering anything would at once "put all the other Images into a disorderly floating, and so raise a little Chaos of confusion, where Nature requires the exactest order" (1970, 36). The 1650s and 1660s, on either side of the Restoration of the monarchy after the regicide and Commonwealth, saw a terrible crisis of public memory in England, reflected in neglected yet obsessive debates among natural philosophers about the neurophysiology of individual memory. After the uncontrolled multiplicity of opinion allowed free rein in the Interregnum, unity had to be imposed not only in worship, dress, and conduct, but in narratives of the personal and political past. "Memory is a slippery thing", wrote a preacher in 1657 (quoted in Cressy 1994, 68), and the reception of Descartes’ physiological psychology in England was driven, in a sense, by the desire not to slip (Sutton 1998, 129-148).
Because the mere roaming of fickle fluids and spirits through the brain’s networks would allow memories to interfere and blend with each other, the English instead constructed systems of internal fixity. In a lecture of 1682, the Royal Society technician Robert Hooke, for example, saw each item in memory as separately stored in order on physical coils of memory in the brain, spirals down which the soul could radiate its attention in calculating the temporal sequence of past experiences (Hooke 1971, 140). Descartes’ innards, then, were too wet, his brain too porous for the English, making memory hostage to fluid animal spirits which, complained Henry More, are "nothing else but matter very thin and liquid". The brain can’t reconstruct motions by itself, as Descartes’ theory required, since it is just a "loose Pulp" of "a laxe consistence" which is no more fit to perform our noble cognitive operations than is "a Cake of Sewet or a Bowl of Curds" (More 1978, 33-4).
The naturalizing of localist or archival models of memory was thus a wishful resistance to Cartesian confusion. For Hooke, individual memory ideas must be "in themselves distinct", so that "not two of them can be in the same space, but that they are actually different and separate one from another" (Hooke 1971, 142). Even though Hooke himself used external aids to memory remorselessly and was an inveterate list-maker, recording the weather, his health, and his every orgasm (Mulligan 1992), his theory of human memory also imposed pure, "cleansed" order on our internal "Repository". If memory traces were active patterned motions, as Descartes argued, loss of control was inevitable: Glanvill complained that "one motion would cross and destroy another…and there would be nothing within us, but Ataxy and disorder" (1970, 39). Far safer, thought the English, for ideas in memory to be themselves passive and independent, to leave it up to the soul or the will to read, decode, and manipulate them (Sutton 1998, 135-156). Kenelm Digby was the first to argue in English that Descartes’ philosophy of the brain could not explain "how thinges are conserved in the memory" (1978, 282). Digby wanted every memory idea, on its entry into the brain, to "find some vacant cell, in which they keep their rankes and files, in great quiett and order; all such sticking together, and keeping company with one an other, that entered in together: and there they lie still and are at rest, untill they be stirred up" by appetite or by the will (1978, 284-5). But the task of the cognitive agent in raiding the spongy brain’s caches and compartments is not easy: when it has trouble recollecting some particular idea from memory (1978, 285-6),
it shaketh again the liquid medium they all floate in, and rooseth every species lurking in
remotest corners, and runneth over the whole beaderoule of them; and continueth this
inquisition and motion, till eyther it be satisfied with retriving at length what it required, or
that it be grown weary with tossing about the multitude of litle inhabitants in its numerous
empire, and so giveth away the search, unwillingly and displeasedly.
Prone to boredom and petulance, lost in its own archive, Digby’s soul is unable to navigate its own liquid empire. Disputes between dynamic and static accounts of memory traces are political as well as empirical, the historical distance afforded by examining these quaint and alien 17th-century debates revealing just the issues about control of the personal past which may still animate brain theory.
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