The Pursuit of Certainty. Shirley Robin Letwin

that God had made man not a “sorry worthless piece fit for no use,”¹ but an image of Himself. They were repelled by the doctrine of predestination, and were convinced that man need believe only in his own power to perfect himself. Since God had written the moral law within the image He made, man had only to exercise his reason to discover it. Thus the Cambridge Platonists found in Scripture a gentler, more generous faith than the puritanism they had inhabited. Far from disdaining anyone who professed somewhat different words, they insisted that character mattered more than creed. Their emphasis fell not on sin or on dogma, but on reason—the “Light of Nature” and “the Candle of the Lord.”

      But from Hume’s standpoint, this exaltation of reason was no great improvement on Presbyterian dogma. The doctrine of the Cambridge Platonists implied that moral truth could be discovered with the same certainty and precision as mathematical truth. And there was no dearth of valiant philosophers who would undertake the task of showing how morals could actually be reduced to an exact science. The most outstanding was Samuel Clarke, regarded during Hume’s youth as England’s leading intellectual light. In some ways Clarke was attractive to a rebel against the Church. His rational arguments for religion had helped to undermine Hume’s faith in the divinity of Christ, and he was in several circles suspected of heresy. He managed nevertheless to advance steadily up the ecclesiastical ladder until he became Rector of St. James, and he gathered around him the most vigorous controversialists and promising young philosophers of the day. The public flocked to hear his lectures against “those atheists Hobbes and Spinoza,” as well as his sermons, full of logic and obscurity, which set forth in cumbrous periods the official morality of the day.

      Clarke’s success came partly from his ability to give a practical and popular form to the abstract, mathematical view of the universe that had been framed in the seventeenth century, under the inspiration of Descartes and Newton, and was now coming into its own. It was a view of the world that tried not to traffic with the textures, colours, and sounds of material things or the feelings of mortal beings, but emphasized quantity—“hard, cold, colourless, silent and dead.”² That this view might be extended to morals had been suggested by Locke, when he occasionally assimilated moral to mathematical truth. However much he differed from the Cambridge Platonists in metaphysics, he spoke their language about morality, about the “eternal and unalterable nature of right and wrong.” But whereas the Platonists had stressed the objective reality of good and evil, Locke’s emphasis fell on the possibility of demonstrating morality in the same way as mathematics. And Clarke went further. He undertook to demonstrate with mathematical exactitude the existence of God and the obligations of natural religion.

      Although Clarke granted that there were many different moral relations, he was certain that they could all be classified and exactly described, and clear conclusions deduced from them. Some actions promoted the good of mankind, some made men miserable, others were neutral. But whatever the action, its tendency and results were always the same. The differences between good and bad actions were as clear and unvarying as the difference between black and white, or the magnitudes of numbers. To deny that I should do for another man what he in a like case should do for me was, according to Clarke, like asserting that “though two and three are equal to five, yet five is not equal to two and three.”¹ Wickedness was “the same absurdity and insolence in moral matters; as it would be in natural things,” to try to alter the relations of numbers or the properties of geometrical figures.² If men sometimes found it difficult to distinguish between good and evil tendencies, it was not because the nature or results of actions were ambiguous, changeable, or questionable, but because the observers were ignorant or deluded.

      Human uncertainty was due to the senses, which presented man with nothing more than a shifting “phatasmagoria [sic] of unrealities,” and indistinguishably confused the accidental and essential. Reason, however, saw the invariable relations between ultimate facts, and the man of reason could no more withhold his assent from the eternal rules of right, derived from unalterable relations, than a man instructed in mathematics could deny a geometrical demonstration he had understood. Circumstances were irrelevant for Clarke, and were never permitted to muddle the clarity and certainty of moral judgements. He saw no problem about deciding what cases were alike, and had no use for the dissenting opinions of men who were prejudiced by education, laws, customs, and evil practices. Indeed, he considered any attempt to examine how men really behaved a concession to Satan. The human being rightly understood was for him an anonymous unit whose duties could be determined in the abstract by formulae. He was, as Pope said, “all seeing,” and daunted by nothing on the “high Priori road.”

      This rational morality was made even more rigid by Clarke’s follower, Wollaston, who, in his monastic retirement in the City, produced a theory that seemed to define sin as lying. It was wrong to kill a man, he argued, because by “so doing I deny him to be a man,” and his theory was hailed as a discovery in morals equal to Newton’s discoveries in astronomy. Whereas Clarke was mainly interested in denying that morality was merely a matter of taste or power, Wollaston deliberately emphasized the uniformity of moral rules for all times and places. Following reason meant, Wollaston insisted even more strongly than Clarke, following universal, abstract rules. What reason commanded in one case inevitably applied to all other cases: “What is reasonable with respect to Quinctius, is so in respect of Naevius. Reason is performed in species.… The knowledge of a particular idea is only the particular knowledge of that idea or thing: there it ends. But reason is something universal, a kind of general instrument, applicable to particular things and cases as they occur.”¹

      In some ways, there was nothing so severe in the moral teaching of Clarke and Wollaston that it should have offended Hume. They encouraged men to endeavour to live well; they did not deny any possibility of happiness on earth; nor did they impose any austerities. It is indeed difficult to discover from the exact science laid down by Clarke and Wollaston what their moral rules required, apart from commanding that a man should not “desire to gain some small profit to himself by doing violence and damage to his Neighbour”² or that he should “endeavour to appease with gentleness rather than exasperate with retaliation.”³ But the assumption underlying their morality was the same as that of the Cambridge Platonists, and of the Kirk, that man was a divided nature, torn between holy reason and brutish passion. Their faith in reason was much higher than the Kirk’s, but their opinion of their body or the passions no better.

      The Cambridge Platonists had found Platonic and neo-Platonic doctrine attractive precisely because it taught that the spiritual world alone was real, that the soul was immortal and could ascend to heaven. It offered the metaphysical basis of Calvinism shorn of superstition and mystical dross, as well as the basis for a complete answer to Hobbes. When the Cambridge men and their followers departed from Plato, it was only to take a more, rather than less, doctrinaire view. They had none of Plato’s sense for the texture and difficulty of truth; they were as certain as their Puritan ancestors had been that they had discovered in Scripture clear answers to all questions about the soul, heaven and hell, and the nature of God. What worried them was not how man could know what he ought to do, but only how he could acquire the will to do what they knew for certain he should.

      Plato’s latter-day followers learned from him mainly that spiritual man and carnal man saw very different worlds, that a true vision could be reached only by conquering fleshly lusts and unifying human nature with the Divine. The rational faculties, they believed, could come into their own only when the heart was purified and the will disciplined, when reason was not clouded over by a “dark, filthy mist of sin.” The good life meant then endeavouring “more and more to withdraw ourselves from these Bodily things, to set our soul as free as may be from its miserable slavery to this base Flesh.”¹ Imagination had to be transcended, and the “eyes of sense” shut before reason would be left free to see the true permanent realities. Clarke described the passions as “unbridled and furious,” the appetites as “inordinate,” and regretted that some men were robust enough to escape the “natural ill consequences of intemperance and debauchery.”² And Wollaston warned even more sternly against the corruption of human nature: “Unless there be some strong limitation added as a fence for virtue, men will be apt to sink into voluptuousness, as in fact the generality of Epicurus’s herd have done (notwithstanding all his talk of temperance,