§72. Empiricism and Nominalism
The next twist in empirical philosophy comes with an effort to overcome the nominalism that has haunted modern empiricism since Ockham. This work, “radical empiricism,” is a theme in the thinkers to be considered in Part II.
Ockham's nominalism exerts pressure on everything in his philosophy, including his unenthusiastic experimentalism. Both the experimentalism and the nominalism pass into modern philosophy through Telesio, Bacon, Hobbes, Gassendi, Locke, and Leibniz. In the twentieth century, their legacy bifurcates into a more consistent nominalism that eschews empiricism (Sellars, Davidson, Rorty), and a more consistent empiricism that eschews nominalism, namely, the radical empiricists. The nominalists view empiricism as inconsistent with their rationalism, criticizing the “dogmas of empiricism” and the “myth of the given,” while the radical empiricists view nominalism as an obstacle to a more consistently empirical empiricism, which takes the form of problematic ontology rather than theorematic epistemology or a theory of meaning.
Modern empiricism began as an effort to modernize Aristotelian natural philosophy, concentrating on methodical experiment rather than desultory observation, and adopting an explicit method of hypothesis instead of a syllogistic epagogery that made no progress. Bacon, Galileo, Gassendi, Boyle, and Newton value experiments for their credibility-conferring power to separate scholarly fantasy from concepts reliably induced on experience, with which others can build. That was in part the legacy of Epicurus to modern empiricism. “All ideas come from the senses, by encounter, analogy, similarity, and combination, with reasoning contributing something too.” But there is a difference. Epicurus is uninterested in the advance of knowledge for its own sake; his interest in knowledge stops with its therapeutic value as medicine against tranquility-poisoning superstition. The modern empiricists make experience experimental, an instrument for the advance of natural knowledge.
Where Epicurus’s problems were ethical, those of modern empiricism are problems of knowledge and call for an experience reformed for experiments.8By the twentieth century modern empiricism seemed vulnerable to the argument that experience offers no real constraint on hypotheses or their verification. Exposing the myth of the given disqualified sensation as a source of preconceptual data; arguments from the underdetermination of theory (Duhem, Quine) seemed to show that experience does not seriously control scientific evidence; a new logic more nimble than Aristotle’s can reconcile any experience with any hypothesis; and when critics of logical empiricism and historians and sociologists of science reconsidered distinctions between evidence and theory, perception and belief, or discovery and justification, they found the terms entangled and inseparable. Thus did nominalism and historicism disabuse themselves of an empiricism ill-matched to their values.
Should we abandon empiricism and dismiss the value of experience from philosophy? That is the argument of the nominalists. But we still respect experience and insist on experiments, expecting to learn from them. There is more to experimental science than logical empiricism avowed, but there is more to experience than this empiricism, mutilated by nominalism, allowed. Radical empiricism eliminates the epistemological preoccupation with ultimate evidence. Describing experience as knowledge is like describing a knife as a cut. Experience is an instrument that can be used more or less artfully, and empiricism is the artful use of experience to advance problems of knowledge.