By David Bruner
In this part I will give a brief summary of Lewis’ construal of conceptual knowledge in MWO.
In the opening chapter of MWO C. I. Lewis prescribes the boundaries of the philosophical domain. Unlike the natural sciences, the dealings of philosophy are said to be exclusively in further investigation of what is already known.
“It is not the business of philosophy, as it is of the natural sciences, to add to the sum total of phenomena with which men are acquainted. Philosophy is concerned with what is already familiar.”
Those who practice philosophy are not to rely on collection of empirical data in order to establish the logical and ethical judgments which they are after, nor are they to prophetically forecast constraints upon what will be the actual findings of metaphysical investigation. Rather,
“just this business of bringing to clear consciousness and expressing coherently the principles which are implicitly intended in our dealing with the familiar, is the distinctively philosophic enterprise.”
Lewis points out that study of logic requires the use of logic as a rule and guide, that inquiry about right and wrong requires a moral sense for direction, and that formulation of principles of interpretation of reality must make use of, “principles of interpretation already immanent [inherent] in intelligent practice.” Lewis claims that philosophy exceeds its responsible bounds when it takes up speculation about what transcends experience and that it is rightly limited to reflective consideration of the ways in which we deal with what is already possessed within ordinary experience. So the ethicist will make it his or her ambition to more clearly define the good, the logician to define the valid, and the metaphysician to define the real all in terms of experience already encountered and our attitudes taken toward it. Yet as antecedent clarifiers of the meanings of the terms which are to be used in whatever ampliative propositions one may make, these definitions which philosophy will attempt to elucidate shall be determinative of the way in which we understand experience. Lewis writes,
“So understood, the principles of the categories, which metaphysics seeks, stand, on the one side, in close relation to experience and can not meaningfully transcend it. But on the other side – or in a different sense – they stand above or before experience, and are definitive or prescriptive.”
This is to say that in philosophy we work to analyze only the content of our experience and our relation to it in order to make explicit and to sharpen our decisions about categorizations of the elements of experience, but that these categorizations as explicated and sharpened determine exactly what we will make of the content of our experience and our relation to it. Again on this point, Lewis explains,
“It is through reflective examination of experience (more particularly of our own part in it or attitude toward it) that we may correctly formulate these principles of the categories, since they are implicit in our practical dealings with the empirically given. But they are not empirical generalizations in the sense that some later experience may prove an exception and thus invalidate them. They formulate an attitude of interpretation or discrimination by which what would be exceptional is at once thrown out of court.”
So philosophy, in bringing into focus the blur of our implicit decisions about how to interpret experience, legislates explicit rules of interpretation of experience which experience itself cannot alter. The explicit rules of interpretation determine how any experience whatsoever is to be understood. These rules of interpretation which philosophy is concerned to bring to conscious light in the form of definitions constitute what Lewis refers to as the a priori in his epistemological design.
The mind’s formation and use of legislative rules of interpretation are an integral part of Lewis’ holistic conception of human cognitive experience which I will here recount in some detail. Lewis, in accord with philosophical tradition, cites two distinct elements in the mind’s experience of the world. He states,
“There are, in our cognitive experience, two elements; the immediate data, such as those of sense, which are presented or given to the mind, and a form, construction, or interpretation, which represents the activity of thought.”
Lewis introduces a conception of these two elements and their relation to one another which emphasizes the activity of thought as the mind’s volitional contribution to knowledge. The given element of experience, the immediate data, is recognized as that aspect of experience which we have no part in creating and which we cannot alter by our thinking. The a priori element is that interpretation which we place upon the given – our abstractions of parts of the given from the whole and the associations we make between the parts of the given and parts of past experiences and relations we have observed between our own actions and parts of these past experiences. Lewis at one point recounts an exemplary illustration of the interplay between the two elements of cognitive experience in a description of his experience of a fountain pen:
“At the moment, I have a fountain pen in my hand. When I so describe this item of my present experience, I make use of terms whose meaning I have learned. Correlatively I abstract this item from the total field of my present consciousness and relate it to what is not just now present in ways which I have learned and which reflect modes of action which I have acquired. It might happen that I remember my first experience of such a thing. If so, I should find that this sort of presentation did not then mean, ‘fountain pen,’ to me… This present classification depends on that learned relation of this experience to other possible experience and to my action, which the shape, size, etc. of this object was not then a sign of.
Lewis, upon encountering a certain array of sense data, purports, by his own thought process, to abstract from the array a single object and to ascribe to that object qualities which he does not at present observe in it based on its apparent similarity to objects which he has observed in the past that exhibited these qualities when acted upon in certain ways. He notes that any number of different interpretations could be applied to the same given array of sense data depending upon the individual mind’s past subjective experience or pragmatic interest, thereby showing that the immediate sense data are indeed given by an external source and that the mode of interpretation is indeed volitionally contributed by the mind itself. Thus Lewis views the two elements in knowledge as operating independently of one another to an extent. The given is clearly independent of the mind’s interpretation since no activity of the mind can in any way control or alter its nature; and while the characteristics of the given serve as stimuli for the mind to interpret it by ascribing to it certain presently unobserved qualities, the decision of the mind to correlate instances of objects like the one at hand with a specific set of presently unobserved qualities is made independently of and antecedently to encountering the given object. Even the decision of the mind to abstract from instances of arrays of sense data somewhat similar to the one at hand parts which can be recognized as instances of similar objects is independent of and antecedent to encountering the given array of sense data. Lewis speaks of this basic interpretation of the given saying,
“The absolutely given is a specious present, fading into the past and growing into the future with no genuine boundaries. The breaking of this up into the presentation of things marks already the activity of an interested mind.”
For Lewis the most fundamental singling out of specific parts of experience from the rest of consciousness involves the mind’s working independently of what is given.
Since its operation is independent of the sense data given to the mind, Lewis views the element in knowledge comprised of the mind’s interpretational contribution as, in itself, entirely abstract from sense data. He claims that the interpretations made by the mind consist of, “concepts,” or terms with specific logical intensions or connotations. Considered in isolation, these concepts are not tied to any specific sense data. Lewis extricates the conceptual element in knowledge from the sensorially given for us by describing it, for expository purposes, as, “that meaning which must be common to two minds when they understand each other by the use of a substantive or its equivalent.” This manner of describing the purely conceptual is illustrative of its purely logical character since it is obvious that despite considerable idiosyncrasy in different minds’ sense data, people still understand one another. Lewis at one place inserts an example of a logical conceptual interpretation bridging the gap of possible sensory variation between two minds:
“What I would point out is, rather, that in the determination of common concepts, the conveying of ideas, such possible idiosyncrasy in the correlated sense feelings is entirely negligible. You and I mean the same by, ‘red,’ if we both define it as the first band in the sun’s spectrum, and if we both pronounce the same objects to be red. It does not matter if neither the red rug nor the first band of the spectrum give to the two of us identical sensations so long as we individually discover that same sense-quality in each thing which we agree in describing as, ‘red.’ ”
So we see that on Lewis’ view concepts in their pure and shareable form are not references to given sense data but consist in logical definitions. Lewis does hold that these logical concepts would be meaningless if they were not referred to specific aspects of sensory experience by each mind that employed them. However, as sharable between two minds, the concept is not necessarily correlated to any specific aspect of sense. He points out that,
“no such concept ever existed, apart from imagery and sensory material, in any human mind. For each individual there must be a correlation of concept with specific sense-quality. But this correlation is intrinsically individual; if it, too, should be shared, we could not verify that fact, and it is not in the least essential to common understanding that it should be.”
For Lewis the mind’s interpretational work is active in the whole of our cognitive experience bringing logical conceptual shareable meaning to given experience. Even the most basic recognitions of facts in experience are said to be supplied a cognitive significance by a concept’s denotation of them. As Lewis remarks,
“The end-terms which for us are thus understood directly by reference to sense and feeling, have still a conceptual meaning; they are not indefinable. This conceptual meaning is shareable; our imagery is essentially not. Thus the end-terms of such analysis are no different than the beginning terms.”
If the mind’s activity of thought in interpreting experience is thus construed, it becomes apparent that what form our completed knowledge will take is up to us to decide. It is up to us to enumerate whatever specific types of sensory occurrences we choose by means of specific concepts and it is up to us to declare these basic concepts to be related to one another in whatever ways we choose. The sum of these decisions about what our attitude will be in interpreting experience amounts to Lewis’ a priori, the clarification and conscious apprehension of which constitutes his proper domain of philosophy.
Lewis’ a priori consists in designations of criteria by which to classify certain parts of experience into categories. When a sensory experience is inducted into a category on account of its displaying a satisfactory amount of the criteria associated with that category, all of the criteria of that category which are not at the moment displayed in the experience are also attributed to the experience. The category is a complete set of characteristics, the fullness of which may be ascribed to a sense experience when enough of the characteristics are present in the sense experience to safely judge that it may be assumed that the rest will be near in following. Categorizing experience is a matter of examining experience for signs cluing us to the applicability of certain categories and if certain of these categories are applied, predicting that other specific experiences will be forthcoming in connection with what is presently experienced, should certain changes take place. So the a priori designation of criteria by which to classify certain parts of experience into categories takes the form of conditional statements. Lewis uses the statement, “If this is round, then further experience of it will be thus and so (the empirical criteria of objective roundness)” as an example of an a priori designation. A more lucid example would be the statement, “If it is an apple, it will feel smooth, appear smallish, round, and red, and have a sweet taste.” The category, “apple,” is designated a priori to denote an experience which exhibits the criteria of being smooth, smallish, round, red and sweet etc. If an experience is encountered which exhibits a good many of these criteria (smoothness, smallness, roundness and redness), I may a posteriori (upon discovery in the world) apply the category of apple to it and in doing so assume that the present experience will lead directly to other experiences such as an experience of a sweet taste if I act in certain ways or if other changes occur.