Russell - A Very Short Indroduction (8 page)

A response would be to distinguish between semantic and pragmatic levels of analysis. At the semantic level Russell’s account applies, and it makes the sentence ‘the man drinking champagne is bald’ literally false, because although he is indeed bald, he is drinking water. At the pragmatic level reference has been successfully made, and a truth conveyed, because this kind of use gets the job done. But Russell might argue that since his analysis is aimed at a certain type of
expression
standardly taken to be specifically referential, what he says holds good: questions of use are a further matter.

This response does, however, raise questions about the relation of use and meaning. If use is a large part of meaning, facts about it have to be taken centrally into account in explaining how expressions function. The question of how much weight is to be placed on use is controversial; one view claims that it comes close to exhausting meaning, others reject this claim. Russell’s theory demands that we think of the semantics of expressions and their uses as at least separable questions.

For this and other reasons mainly related to the philosophically crucial question of reference – of how language hooks onto the world – Russell’s theory of descriptions plays an important role in debates in the philosophy of language. For present purposes it is significant as an example of the analytic technique he applied in his attempts to solve problems in the theory of knowledge and metaphysics, as we shall now see.

Perception and knowledge

One of the central questions of philosophy is: what is knowledge and how do we get it? John Locke and his successors in the empiricist tradition argued that the foundation of contingent knowledge about the world lies in sensory experience – the use of the five senses, aided when necessary by instruments such as telescopes and the like. With this Russell agrees. But empiricism faces challenge from sceptical arguments aimed at showing that our claims to knowledge might often – perhaps always – be unjustified. There are various reasons for this. We sometimes commit errors in perceiving or reasoning, we sometimes dream without knowing that we are dreaming, we are sometimes deluded because of the effects of fever or alcohol. How, on any occasion of claiming to know something, can we be sure that the claim is not undermined in any of these ways?

In
The Problems of Philosophy
(
PP
) in 1912 Russell made his first systematic attempt to address these questions. ‘Is there any knowledge’, he asks, ‘which is so certain that no reasonable man could doubt it?’ He answers in the affirmative; but the certainty, as it turns out, is far from the absolute certainty of proof.

On the basis of straightforward observations about perceptual experience – the fact that, say, a table appears to have different colours, shapes, and textures depending upon variations either in the perceiver or in the conditions under which it is perceived – we can see that there is a distinction to be drawn between the appearances of things and what they are like in themselves. How can we be sure that appearance faithfully represents the reality we suppose to lie beyond it? The question might even arise, as the sceptical points about dreams and delusions suggest, whether we can be confident that there are indeed real things ‘behind’ our sense experiences at all.

To deal with these questions Russell introduces the term ‘sense-data’ to designate the things immediately known in sensation: particular instances in perceptual awareness of colours, sounds, tastes, smells, and textures, each class of data corresponding to one of the five senses. Sense-data are to be distinguished from acts of sensing them: they are what we are immediately aware of in acts of sensing. But they must also, as the considerations of the preceding paragraph show, be distinguished from the things in the world outside us with which we suppose them associated. The crucial question therefore is: what is the relation of sense-data to physical objects?

Russell’s response to the sceptic who questions our right to claim knowledge of what lies beyond the veil of sense-data, or even to think that physical objects exist at all, is to say that although sceptical arguments are strictly speaking irrefutable, there is nevertheless ‘not the slightest reason’ to suppose them true (
PP
17). His strategy is to collect persuasive considerations in support of this view. First, we can take it that our immediate sense-datum experiences have a ‘primitive certainty’. We recognize that when we experience sense-data which we naturally regard as associated with, say, a table, we have not said everything there is to be said about the table. We think, for example, that the table continues to exist when we are out of the room. We can buy the table, put a cloth over it, move it about. We require that different perceivers should be able to perceive the
same
table. All this suggests that a table is something over and above the sense-data that appear to us. But if there were no table out there in the world we should have to formulate a complicated hypothesis about there being as many different seeming-tables as there are perceivers, and explain why nevertheless we all talk as if we are perceiving the same object.

But note that on the sceptical view, as Russell points out, we ought not even to think that there are other perceivers either: after all, if we cannot refute scepticism about objects, how are we to refute scepticism about other minds?

Russell cuts through this difficulty by accepting a version of what is called ‘the argument to the best explanation’. It is surely far simpler and more powerful, he argues, to adopt the hypothesis that, first, there really are physical objects existing independently of our sensory experience, and, secondly, that they cause our perceptions and therefore ‘correspond’ to them in a reliable way. Following Hume, Russell regards belief in this hypothesis as ‘instinctive’.

To this, he argues, we can add another kind of knowledge, namely, a priori knowledge of the truths of logic and pure mathematics (and even perhaps the fundamental propositions of ethics). Such knowledge is quite independent of experience, and depends wholly upon the self-evidence of the truths known, such as ‘1 + 1 = 2’ and ‘A = A’. When perceptual knowledge and a priori knowledge are conjoined they enable us to acquire general knowledge of the world beyond our immediate experience, because the first kind of knowledge gives us empirical data and the second permits us to draw inferences from it.

These two kinds of knowledge can each be farther divided into subkinds, described by Russell as immediate and derivative knowledge respectively. He gives the name ‘acquaintance’ to immediate knowledge of things. The objects of acquaintance are themselves of two sorts:
particulars
, that is, individual sense-data and – perhaps – ourselves; and
universals
. Universals are of various kinds. They include sensible qualities such as redness and smoothness, spatial and temporal relations such as ‘to the left of’ and ‘before’, and certain logical abstractions.

Derivative knowledge of things Russell calls ‘knowledge by description’, which is general knowledge of facts made possible by combination of and inference from what we are acquainted with. One’s knowledge that Everest is the world’s highest mountain is an example of descriptive knowledge.

Immediate knowledge of truths Russell calls ‘intuitive knowledge’, and he describes the truths so known as
self-evident
. These are propositions which are just ‘luminously evident, and not capable of being deduced from anything more evident’. For example, we just
see
that ‘1 + 1 = 2’ is true. Among the items of intuitive knowledge are reports of immediate experience; if I simply state what sense-data I am now aware of, I cannot (barring trivial slips of the tongue) be wrong.

Derivative knowledge of truths consists of whatever can be inferred from self-evident truths by self-evident principles of deduction.

Despite the appearance of rigour introduced by our possession of a priori knowledge, says Russell, we have to accept that our ordinary general knowledge is only as good as its foundation in the ‘best explanation’ justification and the instincts which render it plausible. Ordinary knowledge amounts at best, therefore, to ‘more or less probable opinion’. But when we note that our probable opinions form a coherent and mutually supportive system – the more coherent and stable the system, the greater the probability of the opinions forming it – we see why we are entitled to repose confidence in them.

An important feature of Russell’s theory concerns space, and particularly the distinction between the all-embracing public space assumed by science, and the private spaces in which the sense-data of individual perceivers exist. Private space is built out of the various visual, tactual, and other experiences which a perceiver coordinates into a matrix with himself at the centre. But because we do not have acquaintance with the public space of science, its existence and nature is wholly a matter of inference.

Thus Russell’s first version of a theory of knowledge and perception, as set out in
PP
. It has a brisk common-sense feel about it on first encounter, but it is far from unproblematic. For example, Russell speaks of ‘primitive’ knowledge and describes it as intuitive; but he does not offer an account of what such knowledge is, beyond saying that it does not require the support of anything more self-evident than itself. But this definition is hardly adequate, and it is obscured further when he adds that there are two kinds of self-evidence, only one of which is basic. Does this distinction make sense? What is ‘self-evidence’ anyway? Nor does he consider the possibility that two propositions might contradict each other despite appearing self-evident when considered separately. If this were to happen, which is one to choose, and on what additional principles of self-evidence?

Another criticism levelled at Russell’s view is that it makes an important but questionable assumption about the basic nature of senseexperience. This is that sense-data,
qua
sensory minima such as particular colours, smells, or sounds, are simply given in experience, and are its most primitive elements. But in fact sensory experience is not ‘thin’ and immediate in this way at all. Rather, it is a rich and complex experience of houses, trees, people, cats, and clouds – it is phenomenologically ‘thick’, and sense-data are only arrived at by a sophisticated process of emptying ordinary perceptual experience of everything it normally means to us. Thus we do not see a rectangle and infer that it is a table; we see a table, and when we come to concentrate upon its shape we see that it is a rectangle.

This criticism is undoubtedly right as far as it goes, but there are ways in which it can be accommodated while still allowing us to describe the purely sensory aspect of experience independently of the usual load of beliefs and theories it carries. Since the whole point is that we are trying to justify possession of those beliefs by showing that perceptual experience entitles us to them, we obviously need an account of our perceptual experience considered purely as such, so that we can evaluate its adequacy to the task. Russell’s aim in talking of sense-data is to do just that. Moreover Russell recognized that sense-data are not the immediately perceptually
given
; in writings during the decade after
PP
he points out repeatedly that specifications of sense-data come last in analysis, not first in experience.

Another criticism is that Russell assumes that immediate experience is expressible in propositions which, despite the fact that they describe only what is subjectively ‘given’, can be used as a basis for knowledge of the world. But how can what seems to apply only to private experience, and carries no reference to what is beyond that experience, be the basis for a theory of knowledge? It does not help to say that Russell also allows a priori knowledge of logical principles which permit inferences from these propositions, for there would be no motivation to draw them unless, in addition, the subject possessed some general empirical beliefs to serve as the major premisses in such inferences, and some empirical hypotheses which the inferences in effect test or support. But these are not available to an experiencer possessed only, as Russell presents him, with sense-data and the self-evident truths of logic.

This problem carried weight with Russell himself, and much later (in
Human Knowledge
) he dealt with it by accepting a version of something he otherwise deprecated in the philosophy of Kant, namely, that there have to be some things (other than truths of logic) known to us a priori if knowledge is to be possible at all. This highly important point is discussed in the appropriate place below.

Another problem advanced by critics is that the considerations Russell relies upon to show that there is an appearance-reality distinction do not, as he states them, persuade. The fact that an object looks one colour or shape to one perceiver but another colour or shape to another perceiver, or different colours or shapes to the same perceiver under different conditions – for example, depending upon whether he sees it in daylight or darkness, or from one viewpoint or another – tells us that the question of how objects appear to perception is a complicated matter, but it does not by itself tell us that we are perceiving something other than the object in question.

This criticism is valid as it stands, but it happens that there are other perfectly adequate ways of drawing an appearance-reality distinction, as more recent work in the philosophy of perception shows; so Russell’s arguments here can be regarded – as he regarded them himself – as heuristic, that is, as merely illustrating the point in order to get discussion started.

But this criticism suggests a further and more important one. It is that Russell, like all his predecessors since Descartes and like some of his successors such as H. H. Price and A. J. Ayer, accepted a crucially significant assumption from Descartes. This is that the right startingpoint for an enquiry into knowledge is individual experience. The individual is to begin with the private data of consciousness, and find reasons among them to support his inferences to – or, more generally, beliefs about – a world outside his head. One of the major shifts in twentieth-century philosophy has been the rejection of this Cartesian assumption. Among the serious difficulties with this assumption is that scepticism becomes impossible either to ignore or refute if we accept it. Another is that on such a thin basis we are simply not entitled to think of the solipsistic would-be knower, alone inside his mind, as capable of naming and thinking about his sensations and experiences, still less as being able to reason from them to an external world. Both thoughts push us firmly towards the thought that the proper place to begin epistemology is, somehow, in the public domain.