At the turn of the twentieth century, philosopher and psychologist William James arrived at a theory of truth and knowledge called radical empiricism. By contrast with the empiricism of John Locke and David Hume, for whom sense data acquired meaning insofar as human reason adequately interpreted and acted upon such data, radical empiricism is the idea that truth and meaning are found directly in the relations we perceive among the things that experience presents to us.
James’ radical empiricism addresses the connection between truth and objectivity in relation to a variety of questions in metaphysics and epistemology. Like his theory of pragmatism, which posits that “ideas … become true just in so far as they help us get into satisfactory relation with other parts of our experience” (a knowledge claim is true if it is useful), radical empiricism is less about establishing or apprehending the existence of an underlying reality that transcends perception and more concerned with understanding how we connect sense perception data to enable us to undertake meaningful action.
In The Meaning of Truth, James summarizes radical empiricism as consisting of postulate, fact and conclusion:
- “The postulate is that the only things that shall be debatable among the philosophers shall be things definable in terms drawn from experience.”
- “The statement of fact is that the relations between things, conjunctive as well as disjunctive, are just as much matters of direct particular experience, neither more so nor less so, than the things themselves.”
- “The generalized conclusion is that therefore the parts of experience hold together from next to next by relations that are themselves parts of experience.”
In sum, James writes, “the directly apprehended universe needs … no extraneous trans-empirical connective support, but possesses in its own right a concatenated or continuous structure.” None of this implies the denial of an objective reality, however, or “the slanderous charge that we deny real existence.” After all, James argues, “the existence of the object, whenever the idea asserts it ‘truly,’ is the only reason, in innumerable cases, why the idea does work successfully.”
For James, if we “let the word ‘truth’ represent a property of the idea, cease to make it something mysteriously connected with the object known, then the path opens fair and wide, as I believe, to the discussion of radical empiricism on its merits.” We should understand truth not as a property of things in themselves but as an indication of whether our ideas about the world help us get on in the world: i.e. truth depends on things in the world.
“Only a Creature that Acts Is Capable of Knowing”
After James, a generation of philosophers, including C. I. Lewis and Moritz Schlick, developed their own versions of radical empiricism. In An Analysis of Knowledge and Valuation, Lewis argues that knowledge enables us to anticipate our experiences, given our circumstances. “Only a creature that acts,” Lewis writes, “is capable of knowing; because only an active being could assign to a content of his experience any meaning; could take it to be significant of anything other than what it presentationally is.” If we have experience E and take action A, we can expect E’ to happen. A number of such “terminating judgments” together can constitute one objective assessment about the existence of a thing external to the perceiver.
For example, statements about the feel or taste of an apple allow the perceiver of the apple to form “terminating judgments” that specify the conditions and actions that predict a particular experience such as the specific feel or taste of an apple. An infinite set of “terminating judgments” that predict the feel, taste, color, etc. of an apple can together form the basis of the objective statement that there is an apple here in front of us: “the pragmatic signification of the perceptual apprehension is verified, and the object, or character of the object, which it mediates is found to exist or to be real.”
In April 1950, Roderick Firth published a paper in The Philosophical Review, defending radical empiricism against critics like Roderick Chisholm, who, in “The Problem of Empiricism,” argues that perceptual relativity leads radical empiricism down a path of logical incoherence. Chisholm takes issue with the assumption that sense data always accurately reflect the reality that surrounds the perceiver. Under certain observational conditions, sense data may be a distortion of reality. For example, a person may be looking at a red apple may perceive a green apple because she is colorblind or because of peculiar lighting conditions.
Radical empiricism claims that an R statement about the content of sense experience (redness will appear) accurately conveys the truth of a P statement that there is a physical object, an apple, present. P entails R. It is possible, however, that conditions of observation C distort sense data such that such data do not accurately reflect reality. P and C may be consistent with each other, but P is inconsistent with R. The conjunction of P and C entails not-R. The radical empiricist who concedes perceptual relativity asserts the following contradiction 1) P entails R, and 2) if P and S, then not-R.
In response, the radical empiricist may be tempted to focus on the R statement (redness will appear) rather than the P physical (there is an apple present). This response invokes a set of conditions consistent with P but not R by qualifying new R’ statements with so-called if-clauses, in effect saying that R accurately reflects P under the right conditions (e.g. the perceiver is not color-blind). The radical empiricist would modify R to “discount the distorting physical condition which his critic has mentioned.”
The problem is that this reply descends into an infinite regress. For every R or R’ that accurately reflects P under certain conditions, other conditions may distort R or R’, necessitating the formation of new R statements (R’’, R’’’, etc.) that modify the previous R statement. Unfortunately, “it is impossible to formulate a sense-datum statement, however complex, which could not conceivably be false when a given physical statement is true.”
Firth concedes perceptual relativity and instead focuses on verbal ambiguity within the P statement. For Firth, the P statement is a member of a family of P statements, all of which fall within a range of meaning that applies to the original P statement. Consider the example of seeing water in a well. One summer day, a person identifies the substance in the well as water. Then, on a winter morning, he encounters the same well and says that the substance is ice. It is still be possible to say that the substance is water if we include the qualifying explanation that water solidifies when its temperature drops below 0°C.
We thus have two claims about the water in a well on a winter morning. The first, P, identifies the substance as not water. The second, P’, identifies the substance as frozen water. P and P’ refer to the same thing, but describe it differently. There is no logical inconsistency between the claim that P (this is water) entails R (I can dip my finger into the water because it is a liquid) and the claim that P (this is water) and C (water solidifies when its temperature drops below 0°C) entails not-R (I cannot dip my finger into the water because it is solid when its temperature drops below 0°C). We simply had to clear up what we mean by P and R. Once the verbal ambiguity as to the meaning of the words that underlie P, C and R has been removed, the apparent inconsistency disappears.
In one version of radical empiricism, then, the meaning of truth relies on the meaning of the words we use to describe our experiences, which themselves presume an underlying objective world.
“The Truth Is Out There” versus “The World Is Out There”
In a 1986 essay, Richard Rorty writes that “we need to make a distinction between the claim that the world is out there and the claim that the truth is out there.” Rorty is channeling the spirit of the French Revolution, which demonstrated “that the whole vocabulary of social relations, and the whole spectrum of social institutions, could be replaced almost overnight.” He is also making a foundational epistemological claim: that “to say that the world is out there, that it is not our creation, is to say, with common sense, that most things in space and time are the effects of causes which do not include human mental states.”
By contrast, “to say that truth is not out there is simply to say that where there are no sentences there is no truth, that sentences are elements of human languages, and that human languages are human creations.” In this view, “the world is out there, but descriptions of the world are not.” Like sentences, truth “cannot exist independently of the human.” The world is out there, but “only descriptions of the world can be true or false.” James calls this distinction a “quasi-paradox.” For example, consider counting. “Undeniably,” he writes, “something comes by the counting that was not there before. And yet that something was always true. In one sense you create it, and in another sense you find it.”
While James’ thesis invokes the traditional Kantian distinction between things as they appear (phenomena) and things in themselves (noumena), Rorty’s distinction is influenced by several groundbreaking developments in the philosophy of language, especially Wittgenstein’s thesis that “for a large class of cases—though not for all—in which we employ the word ‘meaning’ it can be defined thus: the meaning of a word is its use in the language.” For Wittgenstein, meaning arises within language games: our words and sentences are interwoven with the context in which we act. If I say “slab!” and point, I might be identifying a piece of stone or issuing an order to bring the slab over to me.
For John Searle, Wittgenstein’s thesis “leaves everything exactly as it is.” That is, “the only ‘foundation’ … that language has or needs is that people are biologically, psychologically and socially constituted so that they succeed in using it to state truths, to give and obey orders, to express their feelings and attitudes, to thank, apologize, warn, congratulate, etc.” The implications go further than this for Rorty. If the “idea that a truth was made rather than found began to take hold of the imagination of Europe” in the aftermath of the French Revolution, the distinction between the claim that the truth is out there and the claim that the world is out there led “to a split within philosophy” between philosophers who “take science as the paradigmatic human activity, and think of science as discovering truth rather than making it” and philosophers who, “realizing that the world as it is described by the physical sciences teaches no moral lesson, offers no spiritual comfort, have concluded that science is no more than the handmaiden of technology.”
For the second group, science has no monopoly on knowledge about the world. Scientists may “invent descriptions of the world which are useful for purposes of predicting and controlling what happens” but “poets and political thinkers invent other descriptions of it for other purposes.” Rorty’s sympathies lie with the second kind of philosopher. The “distinction between the claim that the world is out there and the claim that the truth is out there,” he writes, is necessary if we are ever “to recapture Schiller’s conviction that art and politics together may jointly shape a new humanity.” In other words, the pursuit of truth is not simply about discovering the world, but about transforming it.
Rorty acknowledges, however, that “the difficulty faced by a philosopher who, like myself, is sympathetic to this suggestion, one who thinks of himself as auxiliary to the poet rather than to the physicist, is to avoid hinting that this suggestion gets something right, that my sort of philosophy corresponds to the way things really are,” because “this talk of correspondence brings back just the idea which my sort of philosopher wants to get rid of, the idea that the world or the self has an intrinsic nature.” For this second kind of philosopher, Rorty writes, “explaining the success of science, or the desirability of political liberalism, by talk of ‘fitting the world’ or ‘expressing human nature’ is like explaining why opium makes you sleepy by talking about its dormitive power.” Indeed, “to say that Freud’s vocabulary gets at the truth about human nature, or Newton’s at the truth about the heavens, is not an explanation of anything. It is just an empty metaphysical compliment which we pay to writers whose novel jargon we have found useful.”
Knowledge comes down not to claims that what we say is true but claims that what we say is useful—a claim is true if, and only if, it is useful in our experience. “To say that there is no such thing as intrinsic nature,” for example, “is not to say that the intrinsic nature of reality has turned out, surprisingly enough, to be extrinsic. It is to say that the term ‘intrinsic nature’ is one which it would pay us not to use, an expression which has caused more trouble than it has been worth.” This is not the same as denying truth. As Rorty writes, dropping “the idea of truth as out there waiting to be discovered is not to say that we have discovered that there is no truth out there. It is to say that our purposes would be best served by ceasing to see truth as a deep matter, as a topic of philosophical interest, or ‘true’ as a term which repays ‘analysis.’”
For Rorty, “what Hegel misdescribed as the process of spirit gradually becoming self-conscious of its intrinsic nature was the fact that European linguistic practices were changing at a faster and faster rate, that more people were offering more radical redescriptions of more things than ever before.” One major implication emerges in Kuhn’s The Copernican Revolution, which argues that “we did not decide on the basis of some telescopic observations, or on the basis of anything else, that the Earth was not the center of the universe, that macroscopic behavior could be explained on the basis of micro-structural motion, or that prediction and control should be the principal aim of scientific theorizing. Rather, after a hundred years of inconclusive muddle, the Europeans found themselves speaking in a way which took these interlocked theses for granted.” It was not the result of “applying criteria (nor from ‘arbitrary decision’) any more than individuals become theists or atheists, or shift from one spouse or circle of friends to another, as a result either of applying criteria or of actes gratuits.” Truth is not teleological.
Darwin Eclipses Plato
As I have written elsewhere, Plato argues that reality consists of forms that contain the true and eternal nature of the objects that we perceive via our senses. The world of sensation is a world of mirages, like shadows on a wall. The real world is a fixed realm of abstract forms that lend conceptual truth to the objects we perceive in the material world. For example, consider a chair. We observe innumerable kinds of chairs in the world of sensation. But what is a chair? Given that we see so many representations of the chair, how can we arrive at a universal understanding of what a chair is? What is the essence of chair-ness? Plato claims that the form of chair-ness is accessible to our understanding, and that truth is to be found in the form, not in the individual chairs that appear to our senses.
Plato’s theory of forms has had a long shelf life. But while the tradition is still alive, Platonic essentialism met its kryptonite with Charles Darwin’s theory of evolution by means of natural selection, which ushered in a revolution in how we think about biological reality. Modern biologists think in terms of populations and statistics. For biologists, variation is real, not abstract forms. Mutations and sexual recombination provide the variability that allows populations to adapt to changes in the environment. As a result of this interplay between environmental pressures and developmental processes (primarily) and genes (to a much lesser extent), organisms do not retain fixed forms through the generations.
The most intriguing aspect of Rorty’s notion of truth is that, like the “Nietzschean history of culture, and Davidsonian philosophy of language,” it sees “language as we now see evolution, as new forms of life constantly killing off old forms—not to accomplish a higher purpose, but blindly.” Indeed, “to drop the idea of languages as representations, and to be thoroughly Wittgensteinian in our approach to language, would be to de-divinise the world.” In this view, “substituting dialectic for demonstration as the method of philosophy, or substituting a coherence for a correspondence theory of truth, is not a discovery about the nature of a pre-existent entity called ‘philosophy’ or ‘truth.’ It is changing the way we talk, and thereby changing what we want to do and what we think we are.”
Rorty’s message is not that truth is frivolous or relative, but that it is not teleological. He sees intellectual history, including the history of science, as doing “for the theory of culture what the Mendelian, mechanistic account of natural selection did for evolutionary theory. Mendel let us see mind as something which just happened, rather than as something which was the point of the whole process.” Similarly, we should “think of the history of language, and thus of culture, as Darwin taught us to think of the history of a coral reef.”
That is, “our language and our culture are as much a contingency, as much a result of a thousand small mutations finding niches (and a million others finding no niche), as are the orchids and the anthropoids.” Truth involves the evolution of metaphors, whereby “old metaphors are constantly dying off into literalness, and then serving as a platform and foil for new metaphors,” an “analogy which lets us think of ‘our language’—and thus of the science and culture of twentieth-century Europe—as something that took shape as a result of a great number of sheer contingencies.” In Darwin’s theory of evolution by means of natural selection, species are not essentialist creations of God or nature. They are populations that result from a history of path-dependent adaptations to environmental pressures.
Similarly, the history of human progress is an ongoing path-dependent process of responses to the contingencies and vicissitudes of human affairs. Truth is neither teleological nor arbitrary. Truth depends on human action without being divorced from objective reality because, as James insists, “the existence of the object, whenever the idea asserts it ‘truly,’ is the only reason, in innumerable cases, why the idea does work successfully.”
Correspondence and coherence are the two main ways to think about the nature of truth. The correspondence theory of truth views ideas about reality as accurate or inaccurate depending on how well they correspond to the way things are in the world outside our senses. The coherence theory of truth views ideas about reality as accurate or inaccurate depending on how well they reflect the stories we wish to tell about reality, even if those accounts do not rule out other coherent stories about how we see—or want to see—reality.
Rorty argues that “substituting a coherence for a correspondence theory of truth is not a discovery about the nature of a pre-existent entity called ‘philosophy’ or ‘truth,’” but is simply about “changing the way we talk, and thereby changing what we want to do and what we think we are.” One twentieth-century philosopher for whom this view of truth was deeply problematic was Moritz Schlick, a contemporary of Wittgenstein’s and a leader of the Vienna Circle, for whom science is “the paradigmatic human activity,” and who “think of science as discovering truth rather than making it.” This school of philosophy, logical positivism, claims that statements about reality are meaningful only insofar as they are logically or empirically verifiable.
Schlick points out in The Foundation of Knowledge that “if one is to take coherence seriously as a general criterion of truth, then one must consider arbitrary fairy stories to be as true as a historical report, or as statements in a textbook of chemistry, provided the story is constructed in such a way that no contradiction ever arises.” For Schlick, the coherence theory “fails altogether to give an unambiguous criterion of truth, for by means of it I can arrive at any number of consistent systems of statements which are incompatible with one another.” A statement and its negation can both be coherent, but it is logically absurd to accept both as true.
For Schlick, truth must guide us to a systematic account of the world that rules out other knowledge claims as false. This provides a non-arbitrary way of adjudicating the truth of a statement or its negation. But like Rorty’s thesis, which is based on the work of Donald Davidson, Schlick’s argument largely relies on language as the foundation underpinning knowledge claims. For example, Schlick writes that “knowledge in life and science in some sense begins with confirmation of facts, and … the ‘protocol statements’ (‘statements which express the facts with absolute simplicity,’ such as recordings in a notebook by a lab technician or police detective) in which this occurs stand in the same sense at the beginning of science.”
As a logical positivist, Schlick’s views are closer to Wittgenstein’s picture theory of language, according to which “the move to thought, and thereafter to language, is perpetrated with the use of Wittgenstein’s famous idea that thoughts, and propositions, are pictures” of reality. By contrast, Rorty’s reliance on postmodern conceptions of language is heavily influenced by Wittgenstein’s later notion that a word’s meaning is defined by its use in the language. Rorty insists that language is not so much a medium for the representation of reality as an ever-evolving system of “language games” that enable us to talk about reality in ways that are politically or otherwise useful to us.
As a logical positivist, Schlick’s work falls squarely within the analytic camp of modern philosophy, while Rorty, a postmodernist, falls squarely within the continental one. Both philosophers, however, were influenced by James’ pragmatism and radical empiricism—Schlick in developing his own version of radical empiricism (which was robustly critiqued by W. V. Quine); Rorty in developing his own version of pragmatism. For both, language plays a crucial role in the quest for truth: for Schlick, Lewis and Firth as a medium of representation and, for Rorty, as a tool in language games.
For Schlick and others, the role of language in a theory of radical empiricism adheres more closely to a correspondence model of truth. In Rorty’s Darwinian conception of how we talk about things in the world, the contingency of language adheres more closely to a coherence model of truth. In neither case, however, is the notion of objective reality taken to be absurd. Truth may not be teleological, but it is not arbitrary, if only because “only a creature that acts is capable of knowing.” Action, then, depends on an objective reality with which one interacts more or less usefully—that is to say, truthfully.