Aristotelian Epistemology: Part 1
Formal Contact
Aristotle’s doctrine of knowledge begins in the senses, but it does not end there. This is established by three conditions necessary for cognition. For Aristotle, even abstract ideas such as numbers are ultimately derived from material things, thus all cognition or knowing is dependent on the knowledge of things which lies in sensual contact. The knower must in some way be in material contact with the known. However, we do not speak of pebbles in a creek bed as ‘knowing’ the water they sit in. The knower must also be a living thing; i.e. it must be animated and thus have a soul or psyche (ψυχή, Latin, anima). Likewise, we would not say that a water lily that is alive ‘knows’ the water it sits in. The living (animate) knower must have the faculty of sense perception. These three conditions must be present for cognition to take place, but the latter two—conceived of as a unity and termed ‘the sensitive soul’—are decisive. Aristotle’s doctrine of knowledge begins in the senses, but it ultimately ends in the soul.
Sense is real material contact that modifies the material part of the knower in a particular way that allows for the location of the qualities of an object(s) within a spectrum. “Without immediate contact with the object” the sense “could not do its work” for “what is before us is sensible objects.”1 Take sight for example. Light comes into contact with an object upon which some wavelengths of the spectrum are absorbed as others bounce off of it. This light then comes into contact with the retina of the eye wherein mechanisms in the sense organ (the rods and cones) locate these wavelengths within a spectrum of value and hue. Though many material things other than the object itself (photons and air molecules in the case of sight and sound2) are involved, “…the ultimate point of arrival is one, a single mean, with different measures of being.”3 The senses are therefore passive, acted upon by the objects of sensation.4 There is likewise a multiplicity of senses wherein “each sense then is relative to its particular group of sensible qualities.”5 That is to say, diversification coordinate with (and is determined/limited by) the kinds of possible qualitative distinctions.
This multiplicity aids in locating particular objects and distinguishing them from other objects. Without this “everything would have merged for us into an indistinguishable identity.”6 This ability produces an accurate vision of objective reality. The senses form a unity when more than one sense is directed at one and the same object.7 This is achieved by what is termed the ‘common’ or ‘unifying’ sense. It is important to note that for Aristotle, this unification occurs in the senses, that is, in the body, not in the soul. He does not locate this function in any particular sense organ for common sensible qualities are common to all things. He insists that this unification is in the body, animated by a soul, but not yet mind as such.8 Perceptual image is proper to and only possible in the body/soul (Animate). Modern science identifies this unification as occurring in the nervous system (for example a kind of simplification or editing process wherein raw optical data is compiled and significantly reduced into a single ‘image’ takes place in the optical nerve) and ultimately in the brain. This however, does not impinge upon but indeed bolsters Aristotle’s location of a unifying sense within the materiality of the knower (i.e. the body), for brain and mind are by no means synonymous in Aristotelian thought. The product of this synthetic reproduction is the image or phantom (φαντασία) which is described as ‘ratio;’ a coordination of qualitive (relative) sensual data.9 Image or sense-perception is the product of the activity of the senses.
Though perception (image) is occasioned by reality, it yet remains distinct from reality for it is within the (senses of the) knower. To make this assertion Aristotle uses the analogy of a signet ring or stylus imprinting an image on a clay or waxen tablet. There is real contact, “the activity of the sensible objects and that of the percipient sense is one,”10 and a real image is produced that is dependent upon the object, yet “the impress of a signet-ring [is] without the iron”11 that is to say “the distinction between their being remains.”12 The image is distinguishable from the object because the object is material and the image is not. “[S]ense is affected by what is colored or flavored or sounding...it is indifferent [to the] substance [of the object] …what alone matters is what the quality it has; i.e. in what ratio its constituents are combined.”13 Sense-perception, though produced by contact with reality must be distinguished from it.
At this point it can be asked because the object itself is not known—only its qualities in relation to the knower—is sense-perception knowledge? Aristotle recognizes the reasonableness of the question, the view of many previous philosophers. He references Empedocles among others saying “…the ancients go so far as to identify thinking and perception.”14 Nevertheless, Aristotle cannot affirm this identification, thus his thought can be placed firmly within the Socratic/Platonic tradition however within the particularities of his own thought.
The rejection is three-fold: 1) If Perception is the knowing of reality (thought) then “whatever seems [to be true,] is true.”15 Experience suggests otherwise; things are not always what they seem (Plato had the same objection). The senses do not ‘lie’ so to speak, but the image they produce can be less than accurate and can be erroneously accepted as reality. Aristotle maintains that the senses themselves do not ‘lie’ but simply report to whatever degree of accuracy what is being sensed. Judgment however—which Aristotle describes as taking place automatically upon sense-perception however not located in the senses—can error depending on incomplete sensual data or preconceived notions.16 The sequence, location, and relationship/interaction between perception and judgment will continue to cause difficulties in subsequent Epistemology both classical and modern.
2) As mentioned above, the objects of sense-perception and the perception itself remain distinct. The knowing perception (alone) falls short of the knowing reality. Object cannot be distinguished from subject and ultimately the subject and not the object is what is known.
3) This kind of relative knowledge—knowledge of self, but self in relation (relative) to other objects— is real and functional. Indeed, Aristotle insists that it is preliminary to knowing as such and that it is the kind of cognition proper to animals. But it falls short of describing the kinds of thinking observed in human beings for it cannot (according to Aristotle) account for abstraction.17 Perception as reality is unsatisfactory because such knowledge does not know the real and cannot account for abstract human thought.
These considerations give rise to Aristotle’s positive doctrine of knowledge in human beings. A distinction can be made between the thought taking place in animals and in humans. For Aristotle, this is significant for it admits a difference between animal and human souls. There is something in the human soul that allows it to think in the ways that it does. Aristotle terms this part or faculty of the human soul—mind or nous (νους). This gives rise in Aristotelian thought of an ordering or hierarchy of soul types. In this hierarchy, as summarized by the historian of philosophy Fredrick Copleston:
The higher [kinds of souls] presupposes the lower, but not vice versa. The lowest form of soul is the nutritive or vegetative soul, το θρεπτικόν, which exercises the activities of assimilation and reproduction. It is found, not only in plants, but also in animals; yet it can exist by itself, as it does in plants…Animal, then, possess the higher form of soul, the sensitive soul, which exercises the three powers of sense-perception (το αισθητικόν), desire (το όρεκτικόν), and local motion (το κινητικόν κατα τόπον). Imagination (φαντασία) follows on the sensitive faculty…Higher in scale than the merely animal soul is the human soul [more accurately, the kind of soul possessed by humans]. This soul unites in itself the powers of the lower souls…but has the peculiar advantage in the possession of νους [mind].18
Mind, if it is what allows for cognition as we know it, has necessary characteristics. If it can think any possible thought, must be “capable of receiving any possible form of an object”19 it must have the potential to think anything thinkable. Aristotle continues, “…since everything is a potential object of thought, mind in order to know, must be pure from all admixture [as with the body]”, and “potentially identical in character without being the object [materially].”20 The mind is potentiality and as potentiality cannot be located in the body for the body is actualized/individualized matter. As the part of the soul that is thinking mind cannot be material and must be potentiality. However, as Aristotle articulates the difficulty, “if mind is simple and impassible and has nothing in common with anything else [due to its non-temporal potentiality]; how can it come to think at all. For interaction between two factors is held to require a precedent commonality of natures between the factors.”21 Like is known by like, and mind is like nothing else. This is the central difficulty that shapes Aristotle’s epistemology: how is non-material knowing reconciled with an a priori dependence upon sensual (physical) contact. The problem is contact.
Aristotle first identifies an analogous relationship between sense-perception and rational thought. “[I]f thinking is like perceiving” he argues “it must be either a process in which the soul is acted upon by what is capable of being thought” that is to say, “mind must be related to what is thinkable as sense is to what is sensible.”22 With perception, an object occasions an image in the senses because both are material and make contact. Likewise, “to the thinking soul images serve as if they were the content of perception [i.e. to the material object].”23 Thus thinking, for Aristotle, cannot take place apart from images.24 “When the mind is actively aware of anything it is necessarily aware of it along with [its, or through its] image; for images are like sensuous content except in that they contain no matter.”25 Reality operates in the sense faculties as the image (perception) operates in the mind. Does it not follow then that thought, because it is occasioned by images, is a kind of phantom? Such a conception of the knowledge resolves the difficulty, but it does so by reducing thought to something naturally related to images derived from relative sense-perception and thus ultimately located within the bodily senses. This is not a possibility for Aristotle due to the necessary potentiality of the mind and would be to affirm the identification of perception as reality. The difficulty must be resolved another way; Aristotle proceeds by appealing to the concept of form or eidos (ειδος).
We must consider the idea of ‘form’ in both Aristotle’s metaphysics as well as his psychology to understand the role it plays in his epistemology. In his metaphysical thought “matter is potentiality, [whereas] form [is] actuality.”26 Form actualizes matter; it is what distinguishes a being from potential being and beings from other beings. It is the more ‘real’ part of a thing for it is the internal coherence and final cause of the thing itself. Indeed ‘form’ is of the essence. In a particular thing, ‘form’ is distinguished from matter yet it is truly a part of the thing. An object of potential perception—as a particular thing—is informed matter. in contrast to Platonic ‘forms’ that are not particular to an object but general, ideal, and eternal wherein the object is but an instance. Aristotle’s ‘form’ arises from below, it is object particular, ‘category’ (which also arises from below) and not form is his necessary cognitive mechanism of intelligible sameness. Therefore, things are not only particularized in their materiality, but formally as well; for each thing has its own unique form. Metaphysically, ‘form’ can be distinguished from matter in an object. Furthermore, in psychological perception, an object is distinguished from an image as two related yet distinct realities. Aristotle’s epistemology is established within the interaction between these distinctions.
Sense-perception by its very nature engenders a differentiation that mind-as-form can realize. Perception is related to form because as image (ratio) it touches upon the internal coherence/constitution and differentiation of a thing. Likewise, because it admits of no matter but only quality,27 has the power to receive the sensible form of a thing. This is possible because “the realities it knows are capable of being separated from [metaphysically distinguishable from] their matter.”28 Things can be seen as a composite of form and matter; sense-perception makes this distinction, mind in turn, as immaterial, apprehends the immaterial part (form) of an object. Thus, the part of mind that “belongs to everything”29 that “contains some element common to…all other realities which makes them all thinkable”30 is form. From these Aristotle concludes: “Within the soul the faculties of knowledge and sensation are potentially these objects, the one what is knowable, the other what is sensible. They must be either the thing themselves” which is not possible for “It is not the stone which is present in the soul” or “their forms.”31 There is real material contact in sense perception, this perception is unified via coordinating relative quality, from this ‘rational’ (possessed of ratio) vision the mind infers the form of an object, and alas, there is real formal contact between object and subject. Mind knows form because mind is form and relates to objects formally.
The metaphysical movement of form differentiating potential matter is mirrored in cognition itself: “Actual knowledge is identical with its object: potential knowledge in the individual is in time prior to actual knowledge.”32
Aristotle. De Anima 3. 2, 426a.
Cf. De An. 3. 1.
De An. 3. 7, 431a; also 3. 2, 425b.
Cf. De An. 3. 2, 426a.
De An. 3. 2, 426b.
De An. 3. 1 425b.
Cf. De An. 3. 2.
De An. 3. 1, 425a; 2, 426b.
Cf. De An. 2. 12, A; 3. 2, 426b; 3.
De An. 3. 2, 425b).
De An. 2. 12, B.
De An. 3. 2, 425b.
De An. 2.I 12, A.
De An. 3. 3, 427a.
De An. 3.I 3, 427b.
Cf. De An. 3. 3.
Cf. Ibid.
Copleston, A History of Philosophy. Vol. I, Part II (New York: Image Books, 1962), 70-71.
De An. 3. 4, 429a.
Ibid.
De An. 3. 4, 429b.
De An. 3. 4, 429a.
De An. 3. 7, 431a.
Cf. Ibid.
De An. 3. 8, 432a.
De An. 2. 1, 412a.
Cf. De An. 2. 12, A.
De An. 3. 4, 429b.
De An. 3. 4, 429b.
Ibid.
De An. 3. 8, 431b.
De An. 3. 7, 431a.