Throughout the past year numerous books and articles have been published commemorating the three-hundredth anniversary of the birth of Scottish philosopher David Hume (1711-1776). Writing in National Review, Lawrence Klepp said of Hume that he “is still inspiring and vexing professional philosophers, especially those in the Anglo-American analytic tradition.”
In The New Republic, Amartya Sen declared, “Hume’s influence on the nature and reach of modern thinking has been monumental. From epistemology to practical reason, from aesthetics to religion. . .the intellectual world was transformed by the enlightening power of his mind.”
Hume, an empiricist, did indeed have an impact on epistemological thought, particularly in the realm of moral philosophy – but not for the best. As the late Shirley Robin Letwin wrote in The Pursuit of Certainty, “He set out to destroy the traditional Christian view of man as divided between Divine reason and brute passion and directed his attack at the metaphysics that had since Plato’s time supported it.”
In his work, An Enquiry concerning Human Understanding, Hume attempts to be a more genuine empiricist than predecessors John Locke (1632-1704) and George Berkeley (1685-1753) by rejecting all causes and substances and concluding that speculative knowledge and metaphysics are futile.
For Hume, all valid knowledge is acquired by sensory perceptions that vary in degrees. Hence, all ideas are only copies of sense impressions. We get certain impressions from individual things that are lively and vivid. The idea is a perception of a kind, but less vivid. As a consistent empiricist, Hume denies any radical difference between sensation and ideas.
If ideas are only copies of sense impressions, then if one has an idea, which cannot be referred to a sense impression, that idea must be false. And because there are no sense impressions corresponding to substance or to cause or universals or necessity, Hume holds they do not exist. Thus, with one sweep, there remain no substances, no bodies, no minerals, no organisms, no men; in a word, no things.
Cause and effect, contiguity or succession, do not exist in Hume’s world. “All our reasoning concerning causes and effects” he argued, “are derived from nothing but customs.” Habits or expectations or temporal sequences make people believe one action follows another. They mistakenly hold the force of an idea as a physical force.
Empirical philosophy cannot account for causality (“whatever comes to be has an efficient cause” – Aristotle) because, metaphysically, causes and effects are simultaneous. From experience we do not observe the causal nexus between two billiard balls. Instead we infer (non-empirically) that the power in ball A was transferred to ball B.
David Hume, empiricist and enemy of Christian thought
For Hume, cause exists apart from effect because it cannot be observed. And having separated cause, he proceeds to analyze the notion of cause and finds no effect.
If Hume is right, many disciplines which are known through the intellect, and cannot be justified on purely empirical grounds, become meaningless:
1. Science, which seeks universals and is the knowledge of things through their causes. (There is no science of the individual. The Chemist will study in an individual molecule of zinc only those properties which are common to every molecule of zinc);
2. Mathematics, which depends on the notion of infinity and necessity. (No trigonometric function is empirical, e.g., the Law of Cosines: c²=a²+b²-2ab cos C)
3. History (e.g., Caesar crossed the Rubicon), which is not accepted empirically, but on faith.
Without causality, there can be no philosophical appeal to God, the first cause. Hume wanted to create an order safe from divine interference, so he denied any link to God. He severed the connection between the supernatural order and the natural one. He reduced belief in a supreme being to fideism – reliance on faith alone. Belief in God comes from feelings and customs not from reasoning.
Empirically, there can be no justification of natural laws: not only the natural physical laws of science, but more especially the natural moral laws. All laws must be purely civil.
There can be no value judgments, no “inalienable rights,” no natural rights. There can be nothing beyond animal emotions – sense, appetites, pleasure, pain. By discarding the power of human reason, there can only be feelings or sentiment.
By restricting himself to the empirical, Hume can never be certain of anything. Unless he is perceiving something, he cannot be certain it actually exists. And the only thing that saves him from total skepticism is belief derived from a funny inside feeling.
The renowned modern Catholic philosopher Etienne Gilson concluded that “the influence of Hume was mainly destructive” because “his skepticism, the ultimate conclusion of a movement initiated by Descartes, ended in a sort of desperate nihilism.”
By eliminating all religious foundations from Western Civilization, Hume opened the doors to the radically secular, particularly the utilitarianism of Jeremy Bentham (1748-1832) and John Stuart Mill (1806-1873), which held that pleasure and pain are the only motives governing mankind.
We continue to live in a troubling world that they helped create.