The Book of Memory

by Mary Carruthers

  sense organs (in this drawing just the eyes are shown with channels, but

  similar nervi communicated to all the sense organs) to the sensus com-

  munis, which is also identified as fantasia, pairing ‘‘passive’’ and ‘ active’’

  aspects as Avicenna had done. These are fed to the imaginatio or vis

  formalis, which puts mental images together – simultaneously, estimativa

  acts on these contents of imaginatio, as a phantasm is constructed of

  likeness (formalis) and belief (estimativa). The process produces some-

  thing wholly mental, a conceptual form that human intelligence can

  know and work with. The materials for thinking are thus shown as

  mental creations, phantasmata, a word taken by scholastic commentators

  from Aristotle’s treatise, but which occurs as well in Quintilian’s rhet-

  oric, translated in Latin as imagines. It is important to notice that the

  resulting mental image was considered to be composed of input from all

  the senses. In the context of thinking, the word imago in medieval Latin

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  was not limited solely to the visual sense, though it is also true that the

  visual was regarded as the primary instrument of cognition for most

  people. And finally, the images are themselves emphatically fabricated.

  Fantasia, estimativa, and vis formalis are all agents which put separate

  bits and responses together into a whole sensory experience – they are

  not just recording devices.

  These imagines are made present to the mind as the materials of under-

  standing through the activity called cogitatio, ‘‘cogitation, thinking,’’ and

  from them ideas and thoughts are constructed. In this diagram cogitatio

  receives the phantasms put together by the image-making power (vis

  formalis) and they are made into concepts by vis imaginativa, the activity

  of imagining and conceptualizing (pairing abilities to receive and to act in

  the fashion characteristic of this diagram, and of Avicenna’s analysis). Our

  conceptions in the forms of phantasms, mental images, are finally retained

  and recollected by memory, vis memorativa, the final stage of this con-

  structive process. Notice that memory, like thought and imagination, is

  also vis, an agent, a power, not just a receptacle.

  The path between memory and thinking must be two-way, because

  memories have to be recalled as well as stored. So a sort of valve was

  posited, which would allow images to pass into memory, and also to be

  recalled for cogitation. This was called the vermis, the little worm-like body

  drawn in the diagram between cogitatio and memoria. Moreover, it had

  been observed that people often lower their heads in order to think and

  raise them when trying to recollect something. This was taken as evidence

  for the action of the vermis, opening as needed for recollection, and closing

  for concentrated thinking once one had received from memory the materi-

  als one needed. Without such a valve, it was thought, memories could

  crowd unbidden into the mind, overwhelming and distracting rational

  thought. The vermis is a gatekeeper, of a sort.

  It is striking how entirely imagination is implicated in cognition and in

  memory by this medieval analysis. This aspect is the most astonishing,

  most alien, from the stand-point of our own cognitive psychology. The

  vestiges of our sensations are collected up at the start of the process in the

  sensus communis, but from the instant they are received in bits and pieces

  from their various sources, fictive powers, fantasia, vis formalis, and vis

  imaginativa, go to work. This faculty may or may not make an image that is

  accurate or faithful as a representation of something else: the important

  thing for the procedures of recollection is that such images are constructed.

  They are fashioned by ‘‘gathering up’’ matters (componendi, composing

  them) into a common location.

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  Thomas Aquinas: a seal impressed in wax

  Thomas Aquinas shared the somatic psychology of his sources concerning

  the nature of human perception and the process whereby the soul knows; if

  anything, he insisted more completely than the Arabic commentators on

  the ‘‘embodiment’’ of all kinds of human knowledge.40 All thinking utilizes

  the brain’s phantasms: ‘‘Avicenna erred in saying that once the mind had

  acquired knowledge it no longer needed the senses. For we know by

  experience that in order to reflect on knowledge already gained we have

  to make use of phantasms, and that any injury to the physical apparatus

  underlying these will tend to prevent our using the knowledge we already

  have.’’41 Thus all stages and varieties of knowledge for human beings, from

  the most concrete to the most abstract, are shaped in some way within a

  physical matrix. The phantasms are produced by imaginatio, the image-

  making power, which, like memory, is an ‘‘affection’’ (to use Aristotle’s

  term) or ‘‘motion’’ (to use that of Averroe¨s) of the soul, motions which are

  physiological although not only or simply that, in the way that a house is

  bricks but not just bricks.42

  In his lectures on De anima, Thomas describes the process of sensory

  perception as involving either ‘‘material’’ or ‘‘spiritual’’ change. He gives his

  definition in the context of his discussion of the operations of the five

  external senses. He says, as do his sources, that taste and touch perceive by

  direct contact with their objects, whereas the other three senses perceive

  through ‘‘media.’’ But of those three, ‘‘the sense of sight has a special

  dignity; it is more spiritual and more subtle than any other sense.’’43 The

  senses of touch and taste are composed of all four elements, as the body

  itself is, but the other three of air and water.44 (Keep in mind throughout

  this discussion that the brain, while composed like all the body of four

  elements, is especially moist.) The act of perception for all the other four

  senses involves some kind of ‘‘material’’ change or addition; the organ

  receives material qualities directly from the object emitting them. So, in

  touch and taste ‘‘the organ itself grows hot or cold by contact with a hot or

  cold object,’’ in smell, there is ‘‘a sort of vaporous exhalation,’’ in hearing

  ‘‘movement in space’’ of reverberation. 45 But sight causes a wholly ‘‘spiri-

  tual’’ change, the likeness is received in the eye ‘ as a form causing knowledge,

  and not merely as a form in matter.’’46

  The likeness received by the eye is formed by light, the nature of which

  is crucially relevant to the way in which a visual ‘‘appearance’’ affects the

  eye. Thomas Aquinas says that light is neither wholly physical nor wholly

  spiritual, for ‘‘it is impossible that any [wholly] spiritual or intelligible

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  nature should [fall within the apprehension of] the senses; whose power,

  being essentially embodied, cannot acquire knowledge of any but bodily

  things.’’47 But light is not physical either, for it does not behave like
a

  body having mass.48 The likeness of an object, progressing to the eye

  through air, is formed by light and received ‘‘immaterially’’ in the follow-

  ing way:

  the recipient receives the form into a mode of existence other than that which

  the form has in the agent; when, that is, the recipient’s material disposition to

  receive form does not resemble the material disposition in the agent. In these cases,

  the form is taken into the recipient ‘‘without matter,’’ the recipient being assimi-

  lated to the agent in respect of form and not in respect of matter . . . Aristotle finds

  an apt example of this in the imprint of a seal on wax. The disposition of the wax to

  the image is not the same as that of the iron or gold to the image; hence wax, he

  says, takes a sign, i. e. a shape or image, of what is gold or bronze, but not precisely

  as gold or bronze. For the wax takes a likeness of the gold seal in respect of the

  image, but not in respect of the seal’s intrinsic disposition to be a gold seal.

  Likewise the sense . . . is not affected by a coloured stone precisely as a stone, or

  sweet honey precisely as honey.49

  Once again, he says, the distinction between a spiritual change as here

  described and a material change is that in the latter case the recipient

  (a sense organ) ‘‘acquires a material disposition like that which was in the

  agent’’; that is, it receives heat or cold or smell particles or reverberating

  air – some matter – emitted from what it is perceiving. 50

  The crucial features of Thomas’s understanding of ‘‘spiritual’’ and

  ‘‘immaterial’’ in this context lie in his appeal to the ancient image of the

  seal in wax. For the wax does form a physical likeness of the original seal.

  What he evidently means by ‘‘spiritual’’ is that the wax material does not

  take on the gold or bronze of the original, but not that nothing physiological

  at all happens to it. As Myles Burnyeat has argued, for Aquinas Aristotle’s

  notion of ‘‘spiritual’’ change is the act of perceiving itself, which certainly

  affects us even though the sense organ itself does not change (unlike touch,

  for example, when the skin becomes cold in sensing cold). The seal’s image

  is not just ghostly like that of a photographic slide projected on a screen,

  but is a sort of imprint that effects a real change in the perceiver. The

  phantasms are in some respect physiological; they are materially caused

  (in Aristotle’s terms) by the nature of the brain. What Thomas says here he

  understood in terms of Aristotle’s four ‘‘causes’’ (or aspects) of all created

  things: ‘‘material,’’ ‘‘formal,’’ ‘‘efficient,’’ and ‘‘purposeful.’’ What the eye

  takes from the object via air and light is its ‘‘formal’’ aspect but not its

  ‘‘material’’ one, and this aspect causes the eye to change in the sensation we

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  call ‘‘sight.’’ The change in the eye occurs in the same manner in which

  phantasms are recorded in memory, like a seal in wax.

  A further context for understanding the quasi-physical nature of the

  phantasms is found in Thomas’s comments on De anima, III.iii. Referring

  to Aristotle’s statement (in William of Moerbeke’s translation) that ‘ these

  images dwell within and resemble sense experiences,’ he says, ‘ images . . .

  ‘dwell within’ in the absence of sensible objects, as traces of actual sensations;

  therefore, just as sensations arouse appetitive impulses [emotions] whilst the

  sensed objects are present, so do images when these are absent.’ 51 The

  phantasms themselves are ‘ movements started by actual sensations,’ 52 and

  memory is, in definitions deriving from Aristotle, a ‘ delayed motion that

  continues to exist in the soul.’ 53 Thus in some physical sense – just how is

  difficult to understand because the writers seem themselves unsure on this

  point – recollection involves a re-presentation of images imprinted in the

  matter of the brain’s posterior ventricle,54 which are then ‘ scanned’’ or ‘ seen’

  as objects by the intellect in some way analogous to that in which the eye

  perceived them in the first place. ‘‘The phantasms in the imagination are to

  the intellect as colours to sight; as colours provide sight with its object, so do

  the phantasms serve the intellect’’; knowing differs from sight in that

  ‘‘understanding is an act proper to the soul alone, needing the body . . .

  only to provide its object [the phantasms]; whereas seeing and various other

  functions involve the compound of soul and body together.’’55

  Thomas’s description of how knowledge based on experience-derived

  concepts comes about is also instructive in understanding how he regards

  the corporeal/spiritual nature of phantasms. We come to know a concept

  like ‘‘curvature’’ by means of a hypothesis, an ‘‘as though’’ proposition:

  When . . . the mind understands actually anything precisely as curved, it abstracts

  from flesh; not that it judges the curved thing to be not flesh, but it understands

  ‘‘curved’’ without regard to flesh . . . And it is thus that we understand all

  mathematical objects, – as though they were separated from sensible matter,

  whilst in reality they are not so. 56

  We understand universals by considering ‘‘certain aspects . . . of sense-

  objects . . . in separation or distinctly, without judging them to exist

  separately.’’57

  Here Thomas rejects a Neoplatonic view that universals themselves are

  imprinted in the soul, and that in sense-objects we recognize or recollect

  these prior implantations; he also, clearly, rejects the Avicennan–Averroist

  view that direct knowledge of separately existing universals is possible.

  Indeed, he again shows himself to be a better Aristotelian than many of the

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  commentators he was following. As Sorabji comments, Aristotle’s belief

  that biological growth and conscious activity are both equally powers of the

  soul could lead to the sort of materialism which concludes that conscious

  activity is therefore simply another biological process. But instead, he (and

  Thomas Aquinas with him) ‘‘prefers to deny that biological growth is

  ‘simply’ a physical process – which is not however to say that it is a mental

  one [in the modern sense]. Growth is also a development towards an end.

  And desire, perhaps, is an efficient cause of action towards an end.’’58

  Similarly, for Thomas, objects of thought (e.g. triangle, curvature,

  whiteness) are re-presented in the individual, psycho-somatic phantasms

  produced by sense-objects, but they are not merely such traces in the brain.

  They are abstracted by a process of comparison and contrast, ‘‘related to a

  unity in so far as they are judged by one intellect.’’59 But even in describing

  so purely mental an activity as abstraction seems to us to be, a physical

  analogy persists. Thomas, as we have seen, regards the production of

  phantasms as a process of physical changes (‘‘motion’’); thus, in sight,

  ‘‘the colour-affected air itself m
odifies the pupil of the eye in a particular

  way, i.e. it imprints on it a likeness of some colour, and . . . the pupil, so

  modified, acts upon the common sense.’’60

  We have followed the progress of the likeness, the seal impressed upon

  the stuff of imaginatio and memory, until it is presented to the intellect as

  an object of thought, not of sense only. And we have seen that Thomas

  regards abstracted ideas as being as if distinct, not as actually existing

  separately from the phantasms in the memory. But in his discussion of

  this process in Summa theologiae, Thomas explains that because the phan-

  tasms are products and forms in sense organs, and are of individual objects,

  their mode of existence is different from that of the intellect – how then can

  they cause knowledge? They must somehow be impressed upon the receiv-

  ing intellect as color-affected air modifies the pupil of the eye, an organ

  itself composed of air and water and thus able to be a medium between the

  light-generated, air-borne likeness and the moist brain. The intellectual

  impression is mediated and formed ‘‘by the power of the active intellect,

  which by turning towards the phantasm produces in the passive intellect a

  certain likeness which represents, as to its specific conditions only, the

  thing reflected in the phantasm. It is thus that the intelligible species is said

  to be abstracted from the phantasm; not that the identical form which

  previously was in the phantasm is subsequently in the passive intellect, as a

  body is transferred from one place to another.’’61

  Granted these serial processes are increasingly spiritual and immate-

  rial, it is still crucial to notice that for Thomas Aquinas the activity of

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  thinking and the activity of having a sense perception are fundamentally

  analogous, not fundamentally different. Images, representative like-

  nesses, are fundamental to knowing (one must have knowledge of some-

  thing) even if they have to be produced in something which by definition

  has no matter to be formed. That this is so is a symptom of how basic the

  simile of the seal in wax was to Thomas’s understanding of knowledge,

  perception, and memory. For St. Thomas, the soul is neither a ghost in a