1/9. Descartes on Simple Ideas (2)

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1 1/9 Descartes on Simple Ideas (2) Last time we began looking at Descartes Rules for the Direction of the Mind and found in the first set of rules a description of a key contrast between intuition and deduction. This contrast was connected to the possibility of being able to be aware of simple elements of knowledge on which subsequent complex components could be based. Following on from this contrast, Descartes, in his account of Rule Eight, points out that nothing can be known prior to the intellect but points out that whilst the intellect alone is capable of knowledge that it can be helped or hindered by three other faculties, imagination, sense-perception and memory. Also in the discussion of Rule Eight he points to a distinction within simple natures into spiritual and corporeal types. The argument of Rule Nine adds to these considerations the point that intuition is best understood by a careful comparison with ordinary perceptual vision. When perceiving by means of sight we have the clearest sense of what we are viewing the more closely we focus upon it and most confused perception the more we attempt to diffuse its ray. Not only is this true but the example of craftsmen who concern themselves with very fine operations demonstrates how carefully focused vision can become such that extremely fine differences can be captured by it. For the operation of intuition to become similarly fine I for us to attend to the simplest matters and build from them. It is not until Rule Eleven that Descartes really adds anything to the argument provided in the first seven rules. Here he revisits the ways in which intuition was previously described in Rules Three and Seven. The 1

2 2/9 initial description of intuition in Rule Three contrasted it with deduction whilst the account in Rule Seven contrasted it with enumeration. In the discussion of Rule Eleven however Descartes makes clear the reason for this difference. The contrast between intuition and deduction concerns the different ways these two are cognized as intuition requires only that what is being cognized is clear and distinct whilst deduction involves attending to a sequence. When however deduction is viewed as completed and not attended to in the manner of its operation then we have an enumeration or inductive grasp of something entire. The inductive grasp is based movement from one point to another but does not any longer involve this movement so that a whole is here grasped at once. In this respect the inductive grasp that emerges because of a process of deduction is cognized without need for sequential presentation and is thus experienced in a manner akin to an intuition but is distinct from it in the sense that its components may well not be clear and distinctly understood at the point of the grasp. Rule Twelve is where Descartes systematically sets out his understanding of both our powers of cognition and their objects and here he effectively summarizes and extends the argument. With regard to our powers of cognition he distinguishes four capacities, intellect, imagination, sense-perception and memory. Having distinguished these elements he proceeds to examine the mode of operation of sense-perception, indicating that, since it is part of the body, it is merely passive. Descartes presents sense perception as a mechanism by means of which shapes are impressed upon us. This suggestion is based on seeking for what is common between 2

3 3/9 the specific senses, a commonality justified by an understanding of perception as engaged with proportionate differences so that the differences between colours is equated with that between types of shape. This suggestion of a common element underlying the input of specific senses is further buttressed by the view that, distinct from each specific sense, we also possess a common sense as part of the body. The rationale for this view of a common sense is drawn by means of an analogy between a pen and the human body. The movement of a pen in writing directly effects only its tip but the whole of the pen nonetheless moves when the tip is directed by us. Similarly, suggests Descartes, the human body s parts are integrally connected with each other so that when one part of the body is moved the rest of the body is also engaged and this commonality of movement is carried out by the common sense. The operation of the common sense is also related to the manner in which images derived from the senses are stored in the body and is effectively understood by him as a bodily memory in this respect. If the common sense is what is taken to be moved whenever a part of the body is moved so the ability to move the body is presented as emerging from a particular element of imagination, a specifically corporeal element. Just as the common sense is moved whenever any part of the body is moved however, so the corporeal imagination s directive of movement can effect many parts of the body distinct from the operation of the required movement. This type of corporeal imagination is how Descartes accounts for the appearance of intention in animal movement, an appearance that 3

4 4/9 would suggest the operation in them of reason but which this notion can explain without recourse to intention or reason (so this notion is equivalent to instinct ). The actual power of knowledge is distinguished from the corporeal imagination and described by Descartes as purely spiritual. He understands the particular power of knowledge as distinct in principle from everything bodily and as singular in operation despite being related to the plurality of sensory inputs which it somehow attends to. Although the power of knowledge in particular is what is capable of being active, it is not necessarily so but can also be passive. The power of knowledge can be related to the elements of cognition already distinguished as, in connection with imagination and the common sense, it sees things, to imagination alone, it imagines them and when acting on its own it understands them. Just as the imagination can act upon the intellect so it can in its turn be acted upon by the senses. However it also follows from these descriptions that the intellect cannot take any information from any of the other cognitive capacities when it attends to matters that in themselves are not corporeal in nature. Not only is this the case but for distinct concentration to take place on the part of the intellect with regard to the elements of bodily things is for these elements to be distinguished in thought so that a single thing can emerge from a collection which requires not the sensory presentation of actual things but only what Descartes terms abbreviated representations of them. 4

5 5/9 Now for such concentration on bodily things to take place is to reach to the different ways in which objects can be given to cognition and this requires further attention not merely to abbreviated representation but also to an account of things through their order of cognition rather than through their manner of being sensorily given. When we attend to bodies, for example, we are aware in the ordinary course of things that extension and shape are part of a single way that a body must be sensed. But with respect to cognition it is possible to distinguish extension from shape so that each can be considered distinctly. When we concentrate on the simple elements of body we relate to the elements of them are so simple that they cannot be further divided. Shape, extension and motion are listed as such simple parts of body with the other components of body being composed out of these parts. Taking the consideration of simple natures beyond the concentration on body enables recognition of three types of simple nature: purely intellectual, purely material and common. Simple intellectual natures are those, which the intellect cognizes without reference to any of the other parts of cognition. In order to show that there are such simple intellectual natures Descartes provides a thought experiment, asking us to conceive of how anything taken from bodies could represent the nature of knowledge or volition. These simple intellectual natures are distinguished from simple material natures such as we have previously described and which belong to bodies purely. Both of these types of simple nature are different from those natures that we attribute sometimes to bodies and sometimes to minds. 5

6 6/9 These common simple natures are names and characteristics that we relate to both minds and bodies such unity, duration and existence. Since both bodies and minds participate in these natures they are common between them. However, Descartes adds to these, the idea of common notions which express connections between simple natures and are given not as names and characteristics but as propositions. Included under this heading he gives two examples: things that are the same as a third thing are the same as each other and things that cannot be related in the same way to a third thing are different in some respect which state propositional recognition of the characteristics of similarity and difference. Finally, the things that are fitted under the heading of simple natures need not be cognized positively. We can intuit as well as motion, rest and as well as something, nothing and it is due to the simplicity of these notions in combination with the positive ones that we can state that the rest of knowledge will be grounded on the simple natures. Simple natures are not known in any other way than evidently. The reason for this is that to know a simple nature is to know it completely: it cannot be grasped in a partial manner; it is given all at once or not at all. This is precisely because it is simple and thus can be intuited rather than deduced. If two simple natures are presented in a conjoined manner then the manner of their connection must either be necessary or contingent. A necessary connection between two simple natures occurs when the thought of one them leads to the thought of the other whenever they are grasped distinctly. This is what shows extension and shape to be connected, as 6

7 7/9 motion and time. Necessary connection does not only apply to simple material natures but also to simple intellectual ones though confusion is common here so that the connections are obscured from grasp. The next point Descartes makes is that we cannot understand anything other than simple natures and their mixture with the example given that to understand the properties of a triangle is to understand the simple natures of which it is composed but which could be extended to the simple components of material things. The presentation to our mind of composites is grounded either on the operation of experience or on our own combination. Since experience effectively is based on the combination of the elements of cognition that are sub-intellectual then it follows that we require recourse to the judgment of the intellect to assess the appearances they present to us. Since experience requires a move from the inputs of the senses to the imagination we can see that the process of sensory relation to something has many potentials for error but that the basis of error is not strictly the inputs of the senses or imagination but our judgment of their data. So fundamentally error emerges not from external sources but from our own judgments. The combination of sensory elements together in a composition only has one safe ground which is deduction. However, for deduction to be secure requires attending to the distinct appearances of separable elements of cognition in intuition so that deduction rests upon intuition. Intuition thus concerns the simple natures and their necessary connections but the simple natures themselves are grasped with clear evidence and cannot be reduced to 7

8 8/9 further notions. The argument that they cannot be so reduced is an important point of method since it requires acceptance that certain notions are effectively not further definable and that with them it is useless to even attempt definition. If all knowledge is based on simple natures and their combination however then it does not merely follow, as I mentioned last time, that knowledge is all homogeneous in form, but it also must be the case that distinct bodies of knowledge are not different in terms of degrees of simplicity. Rather, the ultimate nature of each body of knowledge must have the same element of simplicity as every other body of knowledge so that in principle it cannot be true that it is easier to learn one body of knowledge than another. In support of this surprising conclusion Descartes proceeds in his account of Rule Fourteen to describe the general nature of knowledge. Here he argues that all knowledge whatsoever, save that of intuition of particulars, is based on comparison but that what often makes this difficult is that different things often possess a common nature in unequal ways. He then adds two important remarks: The chief part of human endeavour is simply to reduce these proportions to the point where an equality between what we are seeking and what we already know is clearly visible. We should note, moreover, that nothing can be reduced to such an equality except what admits of differences of degree, and everything covered by the term magnitude. (58) These comments reveal that the general method as given in the Rules is one of reduction of all problems to proportionate relations so that a generally mathematical sense can be given to them. If equality can be attained in a comparison only by means of discovery of degrees then all that is 8

9 9/9 cognizable is a magnitude of some sort. Thus even though Descartes clearly distinguishes between simple material natures and simple intellectual ones, the former are conceived of in a manner that assimilates them to the latter. 9