The Pursuit of Certainty. Shirley Robin Letwin

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СКАЧАТЬ to himself about the operations of nature, and then vainly expect that nature—or in truth God—should proceed according to those laws which his maxims had prescribed to him; whereas his narrow weak faculties could reach no further than the observation and memory of some few facts produced by visible external causes, but in a way utterly beyond the reach of his apprehension;—it being perhaps no absurdity to think that this great and curious fabric of the world, the workmanship of the Almighty, cannot be perfectly comprehended by any understanding but His that made it. Man, still affecting something of the Deity, laboured by his imagination to supply what his observation and experience failed him in; and when he could not discover the principles, causes, and methods of Nature’s workmanship, he would needs fashion all those out of his own thought, and make a world to himself, framed and governed by his own intelligence. … They that are studiously busy in the cultivating and adorning such dry barren notions are vigorously employed to little purpose.¹

      Many of the practical conclusions that Locke drew from his philosophy were pleasing to Hume. Since human knowledge falls short of perfectly comprehending what exists, men ought not to think they were at the centre of the universe or try to capture a timeless insight into the whole. They had better reconcile themselves to their more modest powers which vouchsafed them only very partial glimpses of truth. They should concentrate on what they could learn by experience and observation, in order to improve the useful arts, and not yearn to know more. For knowledge of the quality of things was beyond their reach, and served only to employ “idle or over-curious brains. All our business lies at home.”²

      But the other, positive purpose of Locke’s philosophy was just what Hume set out to combat. For Locke intended also that his survey of human understanding and powers “to see to what things they are adapted” would show that although men had not the full blaze of sun to light their way, yet “the candle that is set up in us shines bright enough for all our purposes.”³ He was concerned to defeat not only the pretensions of the scholastics, but also the apparent amorality of Hobbes. And against Hobbes, he argued that man was after all a rational creature, who could discern through his reason a certain and universal moral law. Human powers were not great enough to put any conclusion beyond rational criticism, but man could perfectly well rely on his own powers to guide him in ordinary life and particularly in moral questions. Thus Locke hoped, while clearing away false notions, “to raise an edifice uniform and consistent.”

      His new edifice, however much it seemed to depart from the established picture of man, still emphasized man’s affinity to God. Locke made sensation the first and most primitive source of ideas, but not the sole source of knowledge. It was supplemented not only by another passive power, reflection—“the capacity of the mind to receive impressions made on it by its own operations,” but also by an active power of the mind, intellect, which created ideas of relation—abstract, general, and universal ideas. Repeatedly, Locke reminded his readers that neither sensation nor reflection could produce general or abstract ideas, and that the power of producing them distinguished man from brutes: “this, I think, I may be positive in, that the power of abstracting is not at all in them [brutes]; and that the having of general ideas is that which puts a perfect distinction betwixt man and brutes, and is an excellence which the faculties of brutes do by no means attain to.…”¹ The idea of cause, that is, of the power to cause change, he pointed out, could not be resolved into either sensation or reflection; the mind added to the materials supplied by sensation and reflection an idea of its own creation, the idea of cause and effect. The idea of substance was also admitted by Locke, and made equally independent of sensation and reflection. “I never said that the general idea of substance comes in by sensation and reflection or that it is a simple idea of sensation or reflection,” he replied sharply to the criticism of the Bishop of Worcester, “for general ideas come not into the mind by sensation or reflection, but are the creatures or inventions of the understanding, as I think I have shown.”² For all his talk of the dependence of ideas on sensation, intuition was, after all, fundamental for Locke. It furnished all the basic principles of certainty and knowledge.³

      Locke’s moral theory, which Clarke took over, depended entirely on the assumption that man has a rational faculty linking him to God. Reason was declared to be “natural revelation where the eternal Father of light and fountain of all knowledge communicates to mankind that portion of truth which he had laid within the reach of their natural faculties.”⁴ For Locke, no less than for the Cambridge Platonists, reason was “the Candle of the Lord” in man; it alone could discover the law by which he was to govern himself. As this law was nothing other than the rule God had set down for the governance of man, the nature of God and of virtue were one. Thus morality without God was unthinkable. That was why, despite his desire to extend toleration, Locke excluded atheists: “The taking away of God, though but even in thought, dissolves all. …”¹ And for the same reasons, Locke counselled parents to teach their children how to make their irrational, sensual, animal natures submit to the rule of reason.

      Locke nevertheless performed a most useful service for Hume. By distinguishing the creative, intuitive, synthetic powers of the mind from the passive, discursive, analytic powers of reflection and demonstration, Locke defined Hume’s problem. “Creative” reason was what the ancients called “logos” or “nous,” that is, the faculty of apprehending necessary truths, of discovering the essence of things, the permanent causes or reasons for the existence of facts experienced by the senses. It enabled man to transcend both matter and mortality, and to deal with eternal things—first causes, human destiny, the relation between man and God. Reason was man’s participation in the supreme rational power that shaped the universe, that imposed order on the chaos of matter and directed the world towards a rational end. Whereas the senses, memory, and imagination, which man shared with animals, enabled him to perceive individual things and to remember and collect his impressions, his intellect apprehended the principle of these things. It gave him knowledge of general truth that was not merely the sum of particular truths but a genuine insight into the nature of things, into final and formal causes.

      In order to sever man from God, Hume saw that he needed only to deny “creative” reason. He could then redefine reason as a more limited power to receive ideas, to compare and analyse them, a power that was impressive and distinctive but did not carry man beyond nature. The result would be a “com pleat system of the sciences, built on a foundation almost entirely new, and the only one upon which they can stand with any security.”²

      Since in the terms of Locke’s analysis, the work of the creative intellect was to frame abstract ideas and discover relations, these operations absorbed Hume’s attention. If he could have traced them to some faculty other than intuitive reason, he would have destroyed the argument for placing man above the rest of nature and near to God.

      At the height of his philosophic enthusiasm, Hume was moved by an ambition to follow the method of Newton, “the greatest and rarest genius that ever rose for the ornament of the species,” who had admitted “no principles but such as were founded on experiment.”¹ He too would disdain any traffic with occult qualities and reduce all phenomena to the simplest causes without, however, probing too far. In this mood, he produced a largely mechanistic analysis of mental phenomena. He began by calling Locke’s ideas “perceptions,” and resolved them into two kinds, “impressions” and “ideas.” Impressions included all the “sensations, passions, and emotions as they make their first appearance in the soul”; ideas were the images of these perceptions in thinking and reasoning. Ideas and perceptions were analogous to physical atoms, simple and separable, but connected by association, “a kind of attraction which in the mental world will be found to have as many extraordinary effects as in the natural, and to shew itself in as many and as various forms.”² The rest of the Treatise was devoted to showing that every activity of the mind could be explained without recourse to reason in the traditional sense. To this end, Hume occupied himself primarily with two topics, “Space and Time” and “Causation.”

      The ideas of space and time had always been taken for a prime example of abstract ideas, for they СКАЧАТЬ