View source for Philosophy:Phenomenalism

{{Short description|Metaphysical view that physical objects only exist as sensory stimuli}}

In [[Philosophy:Metaphysics|metaphysics]], '''phenomenalism''' is the view that [[Philosophy:Physical object|physical object]]s cannot justifiably be said to exist in themselves, but only as perceptual phenomena or [[Biology:Stimulus (physiology)|sensory stimuli]] (e.g. redness, hardness, softness, sweetness, etc.) situated in time and in space. In particular, some forms of phenomenalism reduce all talk about physical objects in the external world to talk about ''bundles of [[Philosophy:Sense data|sense data]]''.

==History==
Phenomenalism is a radical form of [[Philosophy:Empiricism|empiricism]]. Its roots as an [[Philosophy:Ontology|ontological]] view of the nature of existence can be traced back to [[Biography:George Berkeley|George Berkeley]] and his [[Philosophy:Subjective idealism|subjective idealism]], upon which [[Biography:David Hume|David Hume]] further elaborated.<ref>{{CathEncy|wstitle=Phenomenalism}}</ref> [[Biography:John Stuart Mill|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. 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 conditional|counterfactual conditional]]s, such as "if I were to have ''y''-type sensations, then I would also have ''x''-type sensations".

As an [[Philosophy:Epistemology|epistemological]] theory about the possibility of knowledge of objects in the external world, however, the most accessible formulation of phenomenalism is perhaps to be found in the ''transcendental idealism'' of [[Biography:Immanuel Kant|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 [[Philosophy:Noumenon|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 [[Religion:God|God]]. Hence, while Berkeley holds that objects are merely bundles of sensations (see [[Philosophy:Bundle theory|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 [[Biography:Ernst Mach|Ernst Mach]], later developed and refined by Russell, Ayer and the logical positivists. Mach rejected the existence of [[Religion:God|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.

[[Philosophy:Logical positivism|Logical positivism]], a movement begun as a small circle which grew around the philosopher [[Biography:Moritz Schlick|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 [[Biography:Bertrand Russell|Bertrand Russell]].<!--more on Russell and knowledge by acquaintance/description?--> The idea of some logical positivists, such as A.J. Ayer and [[Biography:Rudolf Carnap|Rudolf Carnap]], was to apply phenomenalism in linguistic terms, enabling reliable discourse of physical objects, such as tables, in strict terms of either actual or possible sensory experiences.

20th century American philosopher [[Biography:Arthur Danto|Arthur Danto]] asserted that "a phenomenalist, believ[es] that whatever is finally meaningful can be expressed in terms of our own [sense] experience.".<ref name="Danto-Nietzsche">[[Biography:Arthur Danto|Danto, Arthur]], ''Nietzsche as Philosopher'', Ch. 3,  § VI, Macmillan, 1965;</ref> 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 [[Empirical evidence|sense-experience]] ... ."<ref name="danto-connections">[[Biography:Arthur Danto|Danto, Arthur]],  ''Connections to the World'', Ch. 27. Harper & Row, 1989, {{ISBN|0-06-015960-X}}</ref>

To the phenomenalist, objects of any kind must be related to experience. "[[Biography:John Stuart Mill|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 &mdash; or nonphysical objects, if there are any &mdash; 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 ... ."<ref name="danto-connections" />

See for comparison [[Philosophy:Sensualism|Sensualism]], to which phenomenalism is closely related.

==Criticisms==
[[Biography:Roderick Chisholm|Roderick Chisholm]] criticized the logical positivist version of phenomenalism in 1948.<ref name="chisholm">Chisholm, R. "The Problem of Empiricism", ''The Journal of Philosophy'' 45 (1948): 512-7.</ref> C.I. Lewis had previously suggested that the physical claim "There is a doorknob in front of me" necessarily [[Logical consequence|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".<ref name="lewis">C. I. Lewis, ''An Analysis of Knowledge and Valuation'' (LaSalle, Illinois: Open Court, 1946), pp. 240, 248-9.</ref>

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.<ref name="firth">Firth, R. "Radical Empiricism and Perceptual Relativity", ''Philosophical Review''. 1950</ref>

Another criticism of phenomenalism comes from [[Philosophy:Truthmaker theory|truthmaker theory]].<ref>{{cite book |last1=Armstrong |first1=D. M. |title=Truth and Truthmakers |publisher=Cambridge University Press |url=https://philpapers.org/rec/ARMTAT |chapter=1. An introduction to truthmakers|year=2004 }}</ref> Truthmaker theorists hold that the truth depends on reality. In the terms of truthmaker theory: a truthbearer (e.g. a proposition) is true because of the existence of its truthmaker (e.g. a fact).<ref>{{cite encyclopedia |last1=MacBride |first1=Fraser |title=Truthmakers |url=https://plato.stanford.edu/entries/truthmakers/ |website=The Stanford Encyclopedia of Philosophy |publisher=Metaphysics Research Lab, Stanford University |date=2020}}</ref> Phenomenalists have been accused of violating this principle and thereby engaging in "ontological cheating": of positing truths without being able to account for the truthmakers of these truths.<ref name="Asay">{{cite web |last1=Asay |first1=Jamin |title=Truthmaker Theory |url=https://iep.utm.edu/truth-ma/ |website=Internet Encyclopedia of Philosophy}}</ref> The criticism is usually directed at the phenomenalist account of material objects. The phenomenalist faces the problem of how to account for the existence of unperceived material objects. A well-known solution to this problem comes from John Stuart Mill. He claimed that we can account for unperceived objects in terms of counterfactual conditionals: It is true that valuables locked in a safe remain in existence, despite being unperceived, because if someone were to look inside then this person would have a corresponding sensory impression. But this solution doesn't satisfy the truthmaker theorist since it still leaves open what the truthmaker for this counterfactual conditional is. It's not clear how such a truthmaker could be found within the phenomenalist ontology.<ref name="Asay"/><ref>{{cite book |last1=Armstrong |first1=David Malet |title=Cause, Mind, and Reality: Essays Honoring C. B. Martin |publisher=Norwell: Kluwer |url=https://philpapers.org/rec/HEICMA |chapter=C. B. Martin, counterfactuals, causality and conditionals|year=1989 }}</ref>

==Notable proponents==
* Johannes Nikolaus Tetens
* [[Biography:John Foster (philosopher)|John Foster]]
* [[Biography:Colin Murray Turbayne|Colin Murray Turbayne]]<ref>[https://books.google.com/books?id=DsKvAwAAQBAJ&dq=Colin+Murray+Turbayne&pg=PA2451 ''Dictionary of Modern American Philosophers'' Shook, John. 2005  p. 2451 Biography of Colin Murray Turbayne on Google Books]</ref>
==See also==
*{{annotated link|Philosophy:Peripatetic axiom}}

==References==
{{Reflist}}

==Bibliography==
* ''Fenomenismo'' in ''L'Enciclopedia Garzanti di Filosofia'' (eds.) [[Biography:Gianni Vattimo|Gianni Vattimo]] and Gaetano Chiurazzi. Third Edition. Garzanti. Milan, 2004. {{ISBN|88-11-50515-1}}
* [[Biography:Isaiah Berlin|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.&nbsp;16–31.

== External links ==
* {{PhilPapers|category|phenomenalism}}
* {{InPho|idea|436}}

{{Navboxes
|list=
{{Idealism}}
{{philosophy topics}}
{{metaphysics}}
{{epistemology}}
{{philosophy of mind}}
{{positivism}}
}}


[[Category:Theory of mind]]
[[Category:Epistemological theories]]
[[Category:Phenomenology| ]]
[[Category:Empiricism]]
[[Category:Idealism]]
[[Category:Metaphysics of mind]]
[[Category:Logical positivism]]

{{Sourceattribution|Phenomenalism}}