Phenomenalism is the view that physical objects cannot justifiably be said to exist in themselves, but only as perceptual phenomena or sensory stimuli (e.g. redness, hardness, softness, sweetness, etc.) situated in time and in space. In particular, some forms of phenomenalism reduce talk about physical objects in the external world to talk about bundles of sense-data.


Phenomenalism is a radical form of empiricism. Its roots as an ontological view of the nature of existence can be traced back to George Berkeley and his subjective idealism, upon which David Hume further elaborated.[1] John Stuart Mill had a theory of perception which is commonly referred to as classical phenomenalism. This differs from Berkeley's idealism in its account of how objects continue to exist when no one is perceiving them (this view is also known as "local realism"). Berkeley claimed that an omniscient God perceived all objects and that this was what kept them in existence, whereas Mill claimed that permanent possibilities of experience were sufficient for an object's existence. These permanent possibilities could be analysed into counterfactual conditionals, such as "if I were to have y-type sensations, then I would also have x-type sensations".

As an epistemological theory about the possibility of knowledge of objects in the external world, however, it is probable that the most easily understandable formulation of phenomenalism is to be found in the transcendental aesthetics of Immanuel Kant. According to Kant, space and time, which are the a priori forms and preconditions of all sensory experience, "refer to objects only to the extent that these are considered as phenomena, but do not represent the things in themselves". While Kant insisted that knowledge is limited to phenomena, he never denied or excluded the existence of objects which were not knowable by way of experience, the things-in-themselves or noumena, though he never proved them.

Kant's "epistemological phenomenalism", as it has been called, is therefore quite distinct from Berkeley's earlier ontological version. In Berkeley's view, the so-called "things-in-themselves" do not exist except as subjectively perceived bundles of sensations which are guaranteed consistency and permanence because they are constantly perceived by the mind of God. Hence, while Berkeley holds that objects are merely bundles of sensations (see bundle theory), Kant holds (unlike other bundle theorists) that objects do not cease to exist when they are no longer perceived by some merely human subject or mind.

In the late 19th century, an even more extreme form of phenomenalism was formulated by Ernst Mach, later developed and refined by Russell, Ayer and the logical positivists. Mach rejected the existence of God and also denied that phenomena were data experienced by the mind or consciousness of subjects. Instead, Mach held sensory phenomena to be "pure data" whose existence was to be considered anterior to any arbitrary distinction between mental and physical categories of phenomena. In this way, it was Mach who formulated the key thesis of phenomenalism, which separates it from bundle theories of objects: objects are logical constructions out of sense-data or ideas; whereas according to bundle theories, objects are made up of sets, or bundles, of actual ideas or perceptions.

That is, according to bundle theory, to say that the pear before me exists is simply to say that certain properties (greenness, hardness, etc.) are being perceived at this moment. When these characteristics are no longer perceived or experienced by anyone, then the object (pear, in this case) no longer exists. Phenomenalism as formulated by Mach, in contrast, is the view that objects are logical constructions out of perceptual properties. On this view, to say there is a table in the other room when there is no one in that room to perceive it, is to say that if there were someone in that room, then that person would perceive the table. It is not the actual perception that counts, but the conditional possibility of perceiving.

Logical positivism, a movement begun as a small circle which grew around the philosopher Moritz Schlick in Vienna, inspired many philosophers in the English speaking world from the 1930s through the 1950s. Important influences on their brand of empiricism included Ernst Mach — himself holding the Chair of Inductive Sciences at the University of Vienna, a position Schlick would later hold — and the Cambridge philosopher Bertrand Russell. The idea of the logical positivists, such as A.J. Ayer and Rudolf Carnap, was to formulate the doctrine of phenomenalism in linguistic terms, so as to define out of existence references to such entities as physical objects in the external world. Sentences which contained terms such as "table" were to be translated into sentences which referred exclusively to either actual or possible sensory experiences.

20th century American philosopher Arthur Danto asserted that "a phenomenalist, believ[es] that whatever is finally meaningful can be expressed in terms of our own [sense] experience.".[2] He claimed that "The phenomenalist really is committed to the most radical kind of empiricism: For him reference to objects is always finally a reference to sense-experience ... ."[3]

To the phenomenalist, objects of any kind must be related to experience. "John Stuart Mill once spoke of physical objects as but the 'permanent possibility of experience' and this, by and large, is what the phenomenalist exploits: All we can mean, in talking about physical objects — or nonphysical objects, if there are any — is what experiences we would have in dealing with them ... ." However, phenomenalism is based on mental operations. These operations, themselves, are not known from sense experience. Such non-empirical, non-sensual operations are the "...nonempirical matters of space, time, and continuity that empiricism in all its forms and despite its structures seems to require ... ."[3]

See for comparison Sensualism, to which phenomenalism is closely related.


Roderick Chisholm criticized the logical positivist version of phenomenalism in 1948.[4] C.I. Lewis had previously suggested that the physical claim "There is a doorknob in front of me" necessarily entails the sensory conditional "If I should seem to see a doorknob and if I should seem to myself to be initiating a grasping motion, then in all probability the sensation of contacting a doorknob should follow".[5] Chisholm objected that the statement "There is a doorknob..." does not entail the counterfactual statement, for if it were to do so, then it must do so without regard to the truth or falsity of any other statement; but suppose the following statement was true: "I am paralyzed from the neck down and experience hallucinations such that I seem to see myself moving toward the door". If this were true, Chisholm objected, then there could be a doorknob in front of me, I could seem to myself to see a doorknob, and I could seem to myself to be performing the correct sort of grasping motion, but with absolutely no chance of having a sensation of contacting the doorknob. Likewise, he objected that the statement that "The only book in front of me is red" does not entail the sensory statement "Redness would probably appear to me were I to seem to myself to see a book", because redness is not likely to appear under a blue light-bulb. Some have tried to avoid this problem by extending the conditions in the analysandum: instead of "There is a doorknob in front of me" one could have it that "There is a doorknob, and I am not paralyzed, etc." In response, Chisholm objects that if one complicates the analysandum, one must also complicate the analysans; in this particular case, that one must analyse in purely sensory terms what it means not to be paralyzed and so on, with respect to which the same problems would arise leading to an infinite regress.

Another common objection to phenomenalism is that in the process of eliminating material objects from language and replacing them with hypothetical propositions about observers and experiences, it seems to commit us to the existence of a new class of ontological object altogether: the sensibilia or sense-data which can exist independently of experience. Indeed, sense-data have been dismissed by some philosophers of mind, such as Donald Davidson, as mythological entities that are more troublesome than the entities that they were intended to replace.

A third common objection in the literature is that phenomenalism, in attempting to convert propositions about material objects into hypothetical propositions about sensibilia, postulates the existence of an irreducibly material observer in the antecedent of the conditional. In attempting to overcome this, some phenomenalists suggested that the first observer could be reduced by constructing a second proposition in terms of a second observer, who actually or potentially observes the body of the first observer. A third observer would observe the second and so on. In this manner we would end up with a "Chinese box series of propositions" of ever decreasing material content ascribed to the original observer. But if the final result is not the complete elimination of the materiality of the first observer, then the translational reductions that are proposed by phenomenalists cannot, even in principle, be carried out.

Another criticism is that the phenomenalist can give no satisfactory explanation of the permanent possibilities of experience. The question can be asked, "What are the counterfactual conditionals which ground the existence of objects true in virtue of?" One answer given by phenomenalists is that the conditionals are true in virtue of past regularities of experience. However, critics object that this answer leads to circularity: first our actual experience was meant to be explained by the possibility of experience, and now the possibility of experience is meant to be explained by our actual past experience. A further objection to the phenomenalist answer is that generally speaking, conditionals are not true in virtue of their past occurrences. This is because it seems that a conditional could be true even if it never actually obtained, and also past occurrences only confirm that a conditional is true, but never make it so.

Roderick Firth formulated another objection in 1950, stemming from perceptual relativity: White wallpaper looks white under white light and red under red light, etc. Any possible course of experience resulting from a possible course of action will apparently underdetermine our surroundings: it would determine, for example, that there is either white wallpaper under red light or red wallpaper under white light, and so on. On what basis are we to decide which of the hypotheses is the correct one if we are constrained to rely exclusively on sensibilia?[6]

Notable proponents


  1. ^ Wikisource-logo.svg Herbermann, Charles, ed. (1913). "Phenomenalism" . Catholic Encyclopedia. New York: Robert Appleton Company.
  2. ^ Danto, Arthur, Nietzsche as Philosopher, Ch. 3, § VI, Macmillan, 1965;
  3. ^ a b Danto, Arthur, Connections to the World, Ch. 27. Harper & Row, 1989, ISBN 0-06-015960-X
  4. ^ Chisholm, R. "The Problem of Empiricism", The Journal of Philosophy 45 (1948): 512-7.
  5. ^ C. I. Lewis, An Analysis of Knowledge and Valuation (LaSalle, Illinois: Open Court, 1946), pp. 240, 248-9.
  6. ^ Firth, R. "Radical Empiricism and Perceptual Relativity", Philosophical Review. 1950


  • Fenomenismo in L'Enciclopedia Garzanti di Filosofia (eds.) Gianni Vattimo and Gaetano Chiurazzi. Third Edition. Garzanti. Milan, 2004. ISBN 88-11-50515-1
  • Berlin, Isaiah. The Refutation of Phenomenalism. The Isaiah Berlin Virtual Library. 2004.
  • Bolender, John. Factual Phenomenalism: a Supervenience Theory, in SORITES Issue #09. April 1998. pp. 16–31.

External links


In analytic philosophy, anti-realism is an epistemological position first articulated by British philosopher Michael Dummett. The term was coined as an argument against a form of realism Dummett saw as 'colorless reductionism'.In anti-realism, the truth of a statement rests on its demonstrability through internal logic mechanisms, such as the context principle or intuitionistic logic, in direct opposition to the realist notion that the truth of a statement rests on its correspondence to an external, independent reality. In anti-realism, this external reality is hypothetical and is not assumed.Because it encompasses statements containing abstract ideal objects (i.e. mathematical objects), anti-realism may apply to a wide range of philosophic topics, from material objects to the theoretical entities of science, mathematical statement, mental states, events and processes, the past and the future.

Constructive empiricism

In philosophy, constructive empiricism (also empiricist structuralism) is a form of empiricism.


In philosophy, empiricism is a theory that states that knowledge comes only or primarily from sensory experience. It is one of several views of epistemology, the study of human knowledge, along with rationalism and skepticism. Empiricism emphasises the role of empirical evidence in the formation of ideas, rather than innate ideas or traditions. However, empiricists may argue that traditions (or customs) arise due to relations of previous sense experiences.Empiricism in the philosophy of science emphasises evidence, especially as discovered in experiments. It is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world rather than resting solely on a priori reasoning, intuition, or revelation.

Empiricism, often used by natural scientists, says that "knowledge is based on experience" and that "knowledge is tentative and probabilistic, subject to continued revision and falsification". Empirical research, including experiments and validated measurement tools, guides the scientific method.

Epistemological idealism

Epistemological idealism is a subjectivist position in epistemology that holds that what one knows about an object exists only in one's mind. It is opposed to epistemological realism.

Hierarchical epistemology

Hierarchical epistemology is a theory of knowledge which posits that beings have different access to reality depending on their ontological rank.


Holism (from Greek ὅλος holos "all, whole, entire") is the idea that systems (physical, biological, chemical, social, economic, mental, linguistic) and their properties should be viewed as wholes, not just as a collection of parts.The term holism was coined by Jan Smuts. Alfred Adler considered holism as a concept that represents all of the wholes in the universe, and these wholes are the real factors in the universe. Further, that Holism also denoted a theory of the universe in the same vein as Materialism and Spiritualism.

Index of philosophy of mind articles

This is a list of philosophy of mind articles.

Alan Turing

Alexius Meinong

Anomalous monism

Anthony Kenny

Arnold Geulincx

Association for the Scientific Study of Consciousness

Australian materialism

Baruch Spinoza

Biological naturalism

Brain in a vat

C. D. Broad

Chinese room



Consciousness Explained

Critical realism (philosophy of perception)

Daniel Dennett

David Hartley (philosopher)

David Kellogg Lewis

David Malet Armstrong

Direct realism

Direction of fit

Disquisitions relating to Matter and Spirit

Donald Davidson (philosopher)

Dream argument

Dualism (philosophy of mind)

Duration (Bergson)

Edmund Husserl

Eliminative materialism

Embodied philosophy

Emergent materialism

Evil demon

Exclusion principle (philosophy)

Frank Cameron Jackson

Fred Dretske

Functionalism (philosophy of mind)

G. E. M. Anscombe

Georg Henrik von Wright

George Edward Moore

Gilbert Harman

Gilbert Ryle

Gottfried Leibniz

Hard problem of consciousness

Henri Bergson

Hilary Putnam



Indefinite monism


Internalism and externalism

Intuition pump

J. J. C. Smart

Jaegwon Kim

Jerry Fodor

John Perry (philosopher)

John Searle

Karl Popper

Kendall Walton

Kenneth Allen Taylor

Ludwig Wittgenstein

Mad pain and Martian pain

Mental property

Methodological solipsism

Michael Tye (philosopher)


Mind-body dichotomy


Multiple Drafts Model

Multiple realizability

Naming and Necessity

Naïve realism


Neutral monism

Noam Chomsky

Parallelism (philosophy)

Personal identity


Philosophy of artificial intelligence

Philosophy of mind

Philosophy of perception


Pluralism (philosophy)

Privileged access

Problem of other minds

Property dualism

Psychological nominalism


Reflexive monism

René Descartes

Representational theory of mind

Richard Rorty

Ron McClamrock

Self (philosophy)

Society of Mind


Stephen Stich

Subjective idealism


Sydney Shoemaker

Tad Schmaltz

The Concept of Mind

The Meaning of Meaning

Thomas Nagel

Turing test

Type physicalism

Unconscious mind

Wilfrid Sellars

William Hirstein

William James


In philosophy of science and in epistemology, Instrumentalism is a methodological view that ideas are useful instruments, and that the worth of an idea is based on how effective they are in explaining and predicting phenomena. Instrumentalism is a pragmatic philosophy of John Dewey that thought is an instrument for solving practical problems, and that truth is not fixed but changes as problems change. Instrumentalism is the view that scientific theories are useful tools for predicting phenomena instead of true or approximately true descriptions The truth of an idea is determined by its success in the active solution of a problem. A successful scientific theory reveals nothing known either true or false about nature's unobservable objects, properties or processes. Scientific theories are assessed on their usefulness in generating predictions and in confirming those predictions in data and observations, and not on their ability to explain the truth value of some unobservable phenomenon. The question of "truth" is not taken into account one way or the other. According to instrumentalists, scientific theory is merely a tool whereby humans predict observations in a particular domain of nature by formulating laws, which state or summarize regularities, while theories themselves do not reveal supposedly hidden aspects of nature that somehow explain these laws. Initially a novel perspective introduced by Pierre Duhem in 1906, instrumentalism is largely the prevailing theory that underpins the practice of physicists today.Rejecting scientific realism's ambitions to uncover metaphysical truth about nature, instrumentalism is usually categorized as an antirealism, although its mere lack of commitment to scientific theory's realism can be termed nonrealism. Instrumentalism merely bypasses debate concerning whether, for example, a particle spoken about in particle physics is a discrete entity enjoying individual existence, or is an excitation mode of a region of a field, or is something else altogether. Instrumentalism holds that theoretical terms need only be useful to predict the phenomena, the observed outcomes.There are multiple versions of instrumentalism. Instrumentalism is a variety of scientific anti-realism.

Johannes Rehmke

Johannes Rehmke (1 February 1848 – 23 December 1930) was a German philosopher and since 1885 professor at Universität Greifswald, later also provost of this university. He offered sharp criticisms of Kant's approach to epistemology. In his article The Conquest of Subjectivism, Paul Linke pointed out that it was Rehmke who first banned the words, 'subjective,' 'objective,' 'immanent,' and 'transcendent,' from his philosophical vocabulary. He made a courageous break from subjectivism, which was the pervasive philosophical paradigm of the times, and also criticized phenomenalism.

List of epistemologists

This is a list of epistemologists, that is, people who theorize about the nature of knowledge, belief formation and the nature of justification.

Logical positivism

Logical positivism and logical empiricism, which together formed neopositivism, was a movement in Western philosophy whose central thesis was verificationism, a theory of knowledge which asserted that only statements verifiable through empirical observation are meaningful. The movement flourished in the 1920s and 1930s in several European centers.

Efforts to convert philosophy to this new "scientific philosophy", shared with empirical sciences' best examples, such as Albert Einstein's general theory of relativity, sought to prevent confusion rooted in unclear language and unverifiable claims.The Berlin Circle and Vienna Circle—groups of philosophers, scientists, and mathematicians in Berlin and Vienna—propounded logical positivism, starting in the late 1920s.

Outline of philosophy

The following outline is provided as an overview of and topical guide to philosophy:

Philosophy – study of general and fundamental problems concerning matters such as existence, knowledge, values, reason, mind, and language. It is distinguished from other ways of addressing fundamental questions (such as mysticism, myth, or the arts) by its critical, generally systematic approach and its reliance on rational argument. The word "Philosophy" comes from the Greek philosophia (φιλοσοφία), which literally means "love of wisdom".

Philosophy of perception

The philosophy of perception is concerned with the nature of perceptual experience and the status of perceptual data, in particular how they relate to beliefs about, or knowledge of, the world. Any explicit account of perception requires a commitment to one of a variety of ontological or metaphysical views. Philosophers distinguish internalist accounts, which assume that perceptions of objects, and knowledge or beliefs about them, are aspects of an individual's mind, and externalist accounts, which state that they constitute real aspects of the world external to the individual. The position of naïve realism—the 'everyday' impression of physical objects constituting what is perceived—is to some extent contradicted by the occurrence of perceptual illusions and hallucinations and the relativity of perceptual experience as well as certain insights in science. Realist conceptions include phenomenalism and direct and indirect realism. Anti-realist conceptions include idealism and skepticism.

Robert K. Cousins

Robert K. Cousins is a contemporary American playwright and founding contributor to phenomenalism, a neo-existential 'post post modern' approach to theatre that has grown out of the experimental performance work staged by Odd Act Theatre Group.

Cousins is the group's resident playwright and has been writing for them since 2005. His plays have appeared at festivals across North America, opening in Princeton, NJ; Washington, DC; Montreal, Quebec; London, Ontario; and Edinburgh, Scotland.Cousins' plays explore the relationship between reality and fiction. His plays are largely meta-theatrical, focusing on the metaphysics of performance in order to explore the ontology and ethics of existence. Cousins' plays often take the form of a philosophical conflict that trickles down into personal and physical confrontation between the characters. Phenomenalism, which seeks to overcome the personal disconnections bred out of postmodernism, draws on Cousins' dramatized explorations of the nature of reality to break the simulation of the theatrical event and create a more direct confrontation between the artist and the audience.

As a founding member of Odd Act Theatre Group, Cousins' career has developed along with the group. His first full-length play, All the Rabbits, had a modest debut at the Carslake Center in suburban Bordentown, NJ. How the Money Goes, his second full-length, also opened in central New Jersey but transferred to Washington, DC, and has since appeared at the Edinburgh Festival Fringe. Ice Cream Musical: The Ice Cream Musical and A Wild Play have both opened in Canada in Montreal and London, Ontario respectively.

Rudolf Eisler

Rudolf Eisler (7 January 1873 – 14 December 1926) was an Austrian philosopher.

Stephen F. Barker

Stephen Francis Barker is an American philosopher of mathematics, a professor emeritus of philosophy at Johns Hopkins University and a former faculty member at the University of Southern California, the University of Virginia and Ohio State University.Barker did his undergraduate studies at Swarthmore College and earned a doctorate from Harvard University in 1954. While at Harvard, he won the Bechtel Prize in 1951 for his essay, "A Study of Phenomenalism". As a young instructor at the University of Southern California, Harvard awarded him the George Santayana Fellowship for the academic year 1954–55. He joined the Johns Hopkins faculty in 1964.Barker's wife, Evelyn A. Barker, was also a philosopher.

Subjective idealism

Subjective idealism, or empirical idealism, is the monistic metaphysical doctrine that only minds and mental contents exist. It entails and is generally identified or associated with immaterialism, the doctrine that material things do not exist. Subjective idealism rejects dualism, neutral monism, and materialism; indeed, it is the contrary of eliminative materialism, the doctrine that all or some classes of mental phenomena (such as emotions, beliefs, or desires) do not exist, but are sheer illusions.

Three Dialogues between Hylas and Philonous

Three Dialogues between Hylas and Philonous, or simply Three Dialogues, is a 1713 book on metaphysics and idealism written by George Berkeley. Taking the form of a dialogue, the book was written as a response to the criticism Berkeley experienced after publishing A Treatise Concerning the Principles of Human Knowledge.Three important concepts discussed in the Three Dialogues are perceptual relativity, the conceivability/master argument and Berkeley's phenomenalism. Perceptual relativity argues that the same object can appear to have different characteristics (e.g. shape) depending on the observer's perspective. Since objective features of objects cannot change without an inherent change in the object itself, shape must not be an objective feature.

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