Systems
Smith then provides us with an account of the gradual evolution of astronomy as a science. The point of this, as we noted above, is to illustrate the more general point about how we come to understand the world. Smith’s account tells us how one system of astronomy is replaced by another, and it is in the detail of this process that we learn why it is that the scientific method has become such an effective means of satisfying our curiosity. Smith’s account relies upon two basic principles that lead us to prefer one system of thought to another and which provide increasingly intellectually and emotionally satisfactory explanations. The first of these is that if our imagination is to be led smoothly, then there must be as few ‘gaps’14 as possible in a theory. If a theory fails to account for part of the observed phenomenon, then we will notice the gap and the lingering anxiety will remain. The system with the fewest such gaps at any one time is the one most likely to be favoured. New theories arise in response to dissatisfaction at the gaps in existing accounts, and in order to succeed they must not only account for the gap, but also account for all that the preceding theory had explained. A new theory must be ‘more completely coherent’15 than its predecessors.
Smith’s second basic principle is the Newtonian preference for identifying a few simple generalizations that explain a multiplicity of phenomena. Explanatory simplicity – elegance, you might say – not only makes it easier for the mind to follow the theory, but it also avoids the danger of a convoluted account that fails to dispel our anxiety. If the system of ideas necessary to explain a complex phenomenon is as complex as the phenomenon itself, then it will fail to relieve the ‘embarrassment’16 in which we find ourselves. This is itself a product of the desire for systematic knowledge. Our desire for a coherent explanation means that we tend to run too quickly into the belief that our system can account for everything: over-ambition leads to over-complexity and eventually to unease that we are over-reaching.
This is a particular problem in the ‘infancy of science’, when ‘the curiosity of mankind, grasping at an account of all things before it had got full satisfaction with regard to any one, hurried on to build, in imagination, the immense fabric of the universe’.17 Smith’s argument in this respect shows the influence of his teacher Francis Hutcheson. In Hutcheson’s An Inquiry into the Original of our Ideas of Beauty and Virtue (1725), there is a chapter on the beauty of theorems. In it, Hutcheson argues that the human reaction to a coherent intellectual system is an appreciation of its beauty and that this beauty comes from the uniformity that the principles of the theorem provide. For Hutcheson, this has some potentially dangerous side-effects. As he puts it, referring to Samuel Pufendorf (1632–94), of whom he otherwise approves:
How awkwardly does Pufendorf deduce the several duties of men to God, themselves, and their neighbours, from his single fundamental principle of sociableness to the whole race of mankind? The observation is a strong proof, that men perceive the beauty of uniformity in the sciences, since they are led into unnatural deductions by pursuing it too far.18
The beauty, the emotionally and intellectually satisfying nature, of a theory comes from its ability to explain the phenomena at hand in a coherent, gapless fashion which is parsimonious in its core explanatory principles. The ability of a theory to banish anxiety and secure our admiration depends on its ability to explain the observed phenomena and connect them together in the most satisfying fashion possible. We will move from one theory to another when we begin to perceive that it has gaps that it cannot explain, or when in its attempt to plug the gaps it becomes convoluted and overly complex. Smith leads us through the main systems of astronomy showing how each was supplanted by a successor that plugged a gap or provided a more theoretically simple account of nature. For example, the advance made by Copernicus over Ptolemy allowed him to explain astronomy in ‘a more simple as well as a more accurate manner’.19 Similarly, Kepler’s increasingly complex use of analogy led to a theory that was ‘of too intricate a nature to facilitate very much the effort of the imagination in conceiving it’.20
In between these shifts between philosophical systems, the scientists operating within a given system spend their time following through on its implications and refining its account to smooth over any gaps that arise.21 Smith ends his survey with a brief description of Newton’s position that dwells on its success in refining the method of science as well as his ability to supplant the system of Descartes.22 In an interesting observation, Smith explains to us how the adherents of a system of thought commit themselves to a particular way of thinking on an emotional level. This means that they are generally hostile to those who propose a new system and seek to preserve the existing way of thinking. This devotion to systems of thought fascinated him, but it also troubled him because he recognized that it was a barrier to the advance of knowledge. Smith himself, as we noted above, believed that a ‘reality check’ would allow the pragmatic scientist to accept that his system did indeed have a gap that needed explaining. Moreover, in the case of superstitious religions, the preservation of the system in the face of evidence to the contrary becomes a very serious matter indeed. The political side of disputes between the adherents of systems in the advance of knowledge is an area where Smith recognizes the power of vested interests – something that is a running theme throughout his work.23
In the other two essays, on Ancient Physics and Ancient Logics and Metaphysics, he does much the same, though they are far less developed than the Astronomy. One interesting development in the Ancient Physics is the exploration of the observation that we attempt to explain the new by bringing together elements that are familiar to us. Creating a chain of familiar ideas and connecting them together in a new way allows our mind to move more smoothly through the systematic account that is being offered. This also underlines another feature of Smith’s epistemology. Like most of his fellow enlightened Scots, he regards the human mind as a system of classification that is constantly being refined. This means that science has two tasks: the discovery of new elements of experience from observation; and the subsequent systematic arrangement of these through a system of connecting principles. Both of these are vital to its success.
This idea clearly struck a chord with Smith because he makes it central to his explanatory outlook throughout his career.24 When he comes to write his own great books, we see him adopt a methodology that is clearly based on the account developed here. The aim is to work from observation of the phenomenon (morality or the economy) to provide a gapless and coherent system that accounts for what is observed in as simple and smoothly connected a fashion as possible. Moreover, he also draws on the idea of arranging the analysis as the exploration of a single simple principle which provides great explanatory reach demonstrated through a series of illustrations. This allows him to provide a systematic and methodical examination of his subject. As we will see, the Moral Sentiments uses sympathy as its master principle while the Wealth of Nations uses the division of labour.25 Smith’s modern biographer Nicholas Phillipson describes this method as mathematical and drawn from the geometry that was one of his favourite subjects while a student at Glasgow.26 The point is that Smith was committed to the twin ideas of empirical observation and systematic and methodical explanation. The test of his own theories would be whether they could account for all of the elements of the observed phenomenon and do so in a more straightforward and persuasive fashion than his rivals.
Rhetoric
The influence of this attitude towards explanation can also be seen in Smith’s thinking on the style of writing best suited to conveying one’s argument. The discovery of a set of student notes from Smith’s Lectures on Rhetoric and Belles Lettres, together with the posthumously published essay ‘Of the Nature of that Imitation which Takes Place in What Are Called the Imitative Arts’, has given us insight into his views on literary criticism and aesthetics.27 The theory developed there dwells on the sentimental nature of the aesthetic experience, the need for a sense of the style appropriate to the social context, and the need for literature to convey ideas in as clear a fashion as possible.
In his essay on the Imitative Arts,