ATOMISM (Greek ’ατομος [atomos]—indivisible)—the name for scientific and philosophical doctrines according to which all reality, or a certain sphere of reality, may be reduced to indivisible simple elements (atoms), and knowledge about all reality may be reduced to knowledge of the elements that compose it.
PHILOSOPHICAL ATOMISM. The term atomism (in a pejorative sense) to designate philosophical, psychological, and sociological positions opposed to organistic conceptions developed in Naturphilosophie by the philosophers of German Romanticism (F. Schlegel, D. F. Schleiermacher)—was first introduced by F. Schegel (Philosophische Vorlesungen, 1804–1806).
In the philosophy of nature. Atomism in the philosophy of nature is a doctrine in the theory of the construction of matter (inorganic and organic) in which the position that there is an ultimate limit for the divisibility of matter is defended.
Leucippus developed the foundations of the doctrine of atomism. His disciple Democritus developed it further and connected it with experience. Atomism was the last attempt in pre-Socratic philosophy at eliminating aporias advanced by Eleatic philosophy. Some earlier atomistic notions that came from Pythagorean philosophy in connection with Empedocles’ theory of the elements were developed by Plato in the Timaeus (53 c–56 c). Plato presented there a conception of geometrical atoms, that is, he interpreted Empedocles’ elements in terms of the five regular geometrical solids, the perfect polyhedrons (tetrahedron, cube, octahedron, dodecahedron, and icosahedron). The fifth solid (the icosahedron) represented the celestial element (the cosmos).
Peripatetic philosophy also made reference to the principles of atomism. Strato of Lampsacus (active around 288 BC), the third scholarch of the Peripatetic school, accepted the existence of a “dispersed vacuum” and used it to explain differences in the density of bodies. The Alexandrian physician Eristratos (3rd century BC) accepted this conception. Ktesibos (around 270 BC), Philo of Byzantium (2nd century BC), and Hero of Alexandria (1st century BC) applied this conception to mechanics and used it to explain phenomena such as the compressibility of air and the diffusion of wine into water. Atomism in its original version was modified by Epicurus who introduced the conception of a spontaneous and uncaused swerve from the straight line in the atom’s perpendicular motion (παρεγκλισις [parenklisis], Latin clinamen) based on the atom’s weight. This conception was intended to free the world from absolute necessity and to justify free will. Titus Lucretius Carus, a philosopher and poet of the first century BC, made other modifications to the doctrine of atomism. He changed the doctrine of atomism (according to a tradition spanning many centuries in the monotheistic religions) into the most classical form of materialism and naturalism. This atomistic doctrine was critical of all forms of theism. Atomism was present in the Middle Ages, but did not have a strong influence. The character of the age was not prepared to absorb doctrines so radically different from its own. Certain branches of atomism (causalism, mechanicism), thought the translation of a treatise called Pantegni (translated by Constantine Africanus) were developed, especially in the school of Chartres. William of Conches developed the theory of minima naturalia in which he joined the neo-Platonic tradition with the atomism of Democritus (known from fragments of the writings of atomists translated by Adelhard of Bath). The Mottekalemini also developed the doctrine of atomism in the Middle ages. They said, against the theory of hylemorphism, that things are not composed of matter and form but of material atoms that by their nature are uniform and differ only in their accidental properties (accidents). They imagined the world as resembling a disintegrated system the unity of which is maintained only by God. The form of atomism contained in Plato’s Timaeus and Lucretius’ treatise De rerum natura, and also in the writings of other ancient authors (Strato, Hero), were developed by such influential thirteenth century authors as R. Grosseteste (around 1168&ndas;1253) and R. Bacon (1214–1294). They worked to sow that heat is the result of the dispersal of particles as the result of motion. The Epicurean tradition also influence, among others, Nicholas Oresme in his theory of the porosity of bodies, and Nicholas of Autricourt who returned to an atomistic view of matter.
Lucretius’ renovated version of atomism, often regarded as the antithesis of the Aristotelian philosophy of nature, most strongly influenced Renaissance thought (Nicholas of Cusa, Callimachus, Girolamo Fracastora, Agostino Nipho, Jacob Zabarella, Leonardo da Vinci, and Giordano Bruno). Most importantly, as the result of the reception of atomism, the concept of matter (prime matter, of metaphysical provenance) was regarded as inoperative and unsuitable for work in the particular sciences. In the modern philosophy of nature P. Gassendi (1592–1655) deserves most of the credit for the restorationof atomism. In his works De vita, moribus et doctrina Epicuri (1647), Animadversiones in Decimum Librum Diogenis Laërtii, qui est de vita, moribus, placitisque Epicuri (1649), and Syntagma philosophiae Epicuri (1649), he adapted Epicurus’ philosophy of atomism to Church doctrine. The renovated doctrine of atomism immediately met with criticism. Descartes raised the most serious objections. He argued from the position of his philosophical system that extension is a constitutive element of a body, but extension (extensio) is infinitely divisible, and so bodies cannot be composed of indivisible atoms. R. Avenarius (1843–1896) and E. Mach (1838–1916) presented another critique of atomism based on the principles of positivistic philosophy. According to these authors there is no place in a philosophy of pure experience (positivistic philosophy) for subjective constructs such as the concept of the atom or matter. These concepts should be successively eliminated from science in the name of the purity of experience. The postulate that the concept of the atom should be removed from the language of science seemed to be supported by science itself, since the laws of phenomenological thermodynamics, especially the law of increasing entropy, seemed to contradict the reality of atoms. The critique of atomism in empiriocriticism had an important influence on the development of science as it specifically contributed to delaying the development of the kinetic-molecular theory of matter. The critique of atomism also led to a doctrine of energeticism that competed with atomism. According to energeticism, whose leading representative was the famous German scholar and one of the authors of physical chemistry, W. F. Ostwald (1853–1932), only energy exists, but the way space is filled by energy may be both uniform and periodic (granular). According to Ostwald, however, all experiential facts can be explained without resorting to the hypothesis of the atomic structure of reality. The further development of science (static thermodynamics) showed that only the doctrine of atomism is able to explain phenomena that cannot be understood from the point of view of energeticism (the photoelectric effect, Brownian motion).
Atomism in metaphysics. G. W. Leibniz’ doctrine of monadology stated that reality is composed of many elementary individual substances (monads) which are immaterial (non-extended), endowed with internal activity, but isolated from the influences of other monads. Due to pre-established harmony (harmonia praestabilita) all the monads respond to each other, are connected and in harmony. Due to this the monads develop independently as each has its own fate, but they develop in parallel and harmony. According to their degree of perfection, monads are at various levels in the hierarchy of perfection. The monads that correspond to organic bodies correspond to the lowest level, and God (the great Monad) is found at the highest level in the hierarchy and is the source of existence for all other monads.
Atomism in logic. This is a position associated with logical empiricism a refers to questions concerning language. It states that every proposition in a logical sense is an individual (atomic) pro0position or can be presented with the help of logical operators (as a combination of individual propositions by truth functors). This position is based on the ontological doctrine of logical atomism (so called to indicate the plurality and interdependence of things and the laws that govern them) and it holds that the logical expressions of correct language have the same structure as the fragments of reality to which they refer. B. Russell (from 1918) proclaimed the foundation for this position, but L. Wittgenstein provided the inspiration. Russell here applied a cognitive procedure analogous to the one he had earlier used in the Principia mathematica, consisting in a shift from the “result” to logically irremovable “premises”. Logical atoms are more elementary than physical atoms since what physics in a given period regards as the ultimate physical components of matter may be subjected to further logical analysis. The whole truth about the world therefore may be reduced to elementary propositions (which constitute the simplest form of logical propositions and at the same time register so-called atomic facts obtained by the application of scientific procedures), since the truth of all propositions is contained in the truth of elementary propositions.
Atomism in psychology. Atomism in psychology occurs in classical behaviorism (but its roots go back to the sensualism of J. Locke and E. Condillac, and to the associationism of D. Hume and D. Hartley). It also cocurs in so-called atomistic psychology (J. F. Herbart, T. Ziehen, H. Ebbinghaus, E. B. Tichener), as opposed to the principles of Gestalt psychology (M. Wertheimer, W. Köhler) and functional psychology (J. R. Angell, J. Dewey), according to which all psychic life may be reduced to simple elements (psychic atoms). These elements are conceived in the same way as physical atoms, and the atomistic psychologists ascribe to them the status of independent beings, but there are controversies concerning the number and kinds of such elements. Without question, the status of independent beings is ascribed only to expressions. Psychic processes such as perceptions, thoughts, volitional and emotional processes are most often regarded as the result of a corresponding construction built according to defined laws (the law of association and a stable connection between physical stimuli and impressions).
Atomism in sociology. Atomism in sociology as a doctrine associated with utilitarianism (A. C. Helvetius, B. de Mandeville, W. Paley), individualism (M. Weber, M. Stirne, T. Carlyle, R. W. Emerson), and with liberalism (A. Smith, J. Bentham, J. S. Mill). This atomism states that society is only a loose aggregate (historically and logically) of individuals who are autonomous with respect to society. According to this doctrine, the social processes as a whole should be explained as the play of mutual and competing individual interests. The rational decisions of individuals are the only the basis for relations between people, and there is a convergence between external influences and the actions of individuals who are guided by their own interest. Conservatives (L. Bonald, E. Burke) vigorously criticized that position and argued that the concept of the isolated man is a fiction since man has always existed in a society, for a society, and thanks to society. Opposition to social atomism in this context was often characterized as the opposition of organicism and mechanicism.
Natural atomism. D. Sennert (1572–1637) applied the principles of atomism for the first time in chemistry. He developed a compromise hypothesis stemming from the conceptions of Avicenna and certain ideas developed in the Averroistic school in Padua. He stated that substances that can be broken down must be composed of the simple bodies into which they are broken down. These simple bodies are not merely abstract mathematical minimums. They are also physical minimums, i.e., atoms. Sennert postulated the existence of four different kinds of atoms corresponding to the four Aristotelian elements, but he also held that there were elements of a second order, so- called prima mixta that arose from the combination of the Aristotelian elements. Through J. Jung (1587–1657) this conception reached R. Boyle (1627–1691). Boyle primarily developed its critical aspect both with regard to the Aristotelian theory of four elements and the alchemical theory of three spagiric elements (sulphur, mercury, salt). Boyle’s idea that matter has corpuscular structure (or texture) was further developed by I. Newton (1642–1727). In his work on optics (Opticks, 1704), he postulated on the basis of theological and teleological premises that matter was created by God in the form of corpuscles. These corpuscles joined together into bigger and bigger aggregates to create a continuum of structures joined together by successively weaker forces. The lest elements of the continuum (the biggest and at the same time the most weakly joined particles) can influence chemical processes and the colors of natural bodies. The Croation scholar R. Bokovic (1711–1787) presented another version of atomism. Although his atomism had no influence on the development of science in the 18th and 19th centuries, it is closer to the theories of matter formulated in contemporary physics. Bokovic was inspired by Newton’s physics and Leibniz’ metaphysics and held that in continuous matter there are points that are centers of rotary motion. These points perform the role of atoms. The rotary motion they cause in turn causes other points (atoms) to be inclined toward them. This would provide a causal explanation of the phenomenon of universal gravity. J. Dalont (1766–1844) made direct reference to Newtonian atomism. He arrived at his atomistic theory by way of physics in his study of the nature of gases (methane, ethane) and liquids (water). He applied the theory in chemistry to explain the composition of chemical compounds. Dalton’s principles for explaining how elements are joined in chemical compounds was later called the law of definite proportions (for which the atomistic theory provided a context for rational justification) and they contributed to the rejection in the nineteenth century of Berthollet’s chemical theory that particles may join together in arbitrary relations. Dalton, however, did not identify the corpuscular theory with the theory of atomism, and we may not treat his views as ultimate proofs for the corpuscular theory of matter, but merely as a theory concerning the construction of the particles in chemical compounds. The theory of atomism (even understood in such a limited scope) played an important role in chemistry and physics. In chemistry this theory contributed primarily to the discovery of a classification of elements, Mendelev’s periodic table of elements, which is today regarded as correct, and in physics it led to the development of fundamental disciplines such as static thermodynamics (L. Boltzmann, M. Smoluchowski), the physics of stable bodies, atomic physics, and nuclear physics.
M. Oster, Roger Joseph Boscovich als Naturphilosoph, Kö 1909; D. Nedelkovitch, La philosophie naturelle et relativiste de R. J. Boscovich, P 1922; C. Bailey, The Greek Atomists and Epicurus, Ox 1928, repr. NY 1964; D. Hadzits, Lucretius and his Influence, NY 1935; R. Ramsauer, Die Atomistik des Daniel Sennert, Kiel 1935; V. E. Alfieri, Gli atomisti, Bari 1936; B. Rochot, les travaux de Gassendi sur Épicure et sur l’atomisme, 1619–1658, P 1944; E.J. Dijksterhuis, De Mechaniserung van het Werelbereld, A 1950 (The Mechanization of the World Picture, Ox 1961, 8–13, 200–209, 277–279, 418–431); G. Müller, Die Darstellung der Kinetik bei Lukrez, B 1959; P. Boyance, Lucrèce et l’Épicurisme, P 1963; F. von Jürss, R. Müller, E. G. Schmidt, Griechische Atomisten, L 1973; Swieżawski DF V 162– R. Sorabij, Time, Creation and the Continuum, Lo 1983; S. Makin, The Indivisibility of the Atom, AGPh 71 (1989), 125–149; Atoms, Pneuma, and Tranquillity: Epicurean and Stoic Themes in European Thought, C 1991; U. Hirsch, Relativität und Erklärbarkeit der Wahrnehmungen in ihrer Bedeutung für Demokrits Atomtheorie, Antike Naturwissenschaft und ihre Rezeption 1–2 (1992), 242–252; M. J. White, The Continuous and the Discrete: Ancient Physical Theories from a Contemporary Perspective, Ox 1992; M. Emily, Daniel Sennert on Matter and Form: At the Juncture of the Old and the New, Early Science and Medicine 2 (1997), 272–299; Gassendi et l’Europe (1592–1792). Actes du colloque international de Paris “Gassendi et sa postérité (1592–1792)”, P 1997.
Zenon E. Roskal
ATOMISM IN INDIAN PHILOSOPHY. Most of the schools of Indian philosophy accept an atomistic conception of matter’s construction, although not all school elaborate upon this in detail. All schools accept four elements (mahabhuta): earth, water, fire, and air, which are built out of atoms (anu, paramanu), as vehicles of basic sensory qualities: odor, taste, color, and touch. Some schools that consider the problem of the intellect and soul also accept that they have the size of an atom.
We find the question of atoms as early as the Upanishads where the immense greatness (ananta) of space (akasha) is presented in opposition to the infinitesimal size (anu) of prana, or life force. Atman (the soul or self) is compared both to space and to prana—“greater than the greatest, lesser than the least”, which led European interpreters to describe the thinking of the Upanishads as “logical paradox”. This problem was passed on to Vedanta philosophy, especially Badarayana, where both infinite greatness and atomic smallness are interpreted as marks of brahman, which is the only reality.
According to Uddalaki Aruni (the Upanishad Chandagya) material also, although it has magnitude, can be divided into atoms that have no magnitude. He holds that all being (sat) has an atomic structure. The senses, the mind, and souls are also of the magnitude of an atom.
We find the most advanced atomism in the philosophical texts of Jainism where atomism extended to the four elements, the senses, and the mind, and in addition the soul (jiva) has the size of an atom. Thereby the soul can be displaced as quick as lightning anywhere in the cosmos to be reincarnated (samsara) according to the karman it has accumulated, and after it achieves liberation it takes its place at the highest point in the universe, in extra-cosmic space (akasha).
Bhaskara presented a similar conception of the soul (atman), which is the size of an atom (and occupies a place in the heart), and it vivifies the whole body, analogous to a drop of sandal oil which fills a room with its odor. Other thinkers of the Vedanta school taught that atman and the soul are omnipresent, but not atomic.
The Indian materialists (lokayata) recognized only four elements that have atomic structure, while they regarded the senses, the mind, consciousness, and the soul as accidental operations of the elements.
The Buddhists of the Abhidarma schools accepted atoms of the four elements as the basic elements (dharma) of reality. They exist only for a moment (anitya) and so they are transitory and insubstantial. The five basic and ten additional sensory qualities arise from different combinations of atoms. For the Yogacara school, atoms like other dharmas are only categories of the phenomena of consciousness.
Philosophers of the Samkhya and Yoga schools hold that the elements (the gross elements) are the final stage in the evolution of proto-matter (prakrti). The elements are secondary to pure qualities, which are also called subtle elements (tanmatra). Without going into a detailed discussion of the question (which is irrelevant to the method and thematic interests of these schools) they hold that the five elements have an atomic structure.
The Nyaya and Mimamsa schools hold a secondary cosmology in relation to Vaishesika, along with the atomism of the latter.
The thinkers of the Vaishesika school worked on the question of atoms with the most detail and so this school is often called the Indian school of atomists. They hold that the atoms of the four elements are fundamental elements (padartha) that belong to the category of substance, and they are eternal, indivisible, without magnitude, and infinite in number, as opposed to eternal but individual all-penetrating substances (ether, space, and time). Substances of intermediate dimensions, which are many in number and impermanent, arise from the combination of atoms (their material cause) with the participation of space and time (as instrumental causes). Sine atoms lack awareness, their motion, which leads them to combine into secondary substances, requires the action of the consciousness of a creator. Therefore among the universal instrumental causes they mention God (Ishvara), his consciosness, his will, and his action. The process of the combination of atoms has several stages. Frist two atoms combine into a pare called the bi-atom (dvyanuka), and four tri-atoms (tryanuka), and four tri-atoms combine into a quadro-atom (caturanuka). The quadro-atom has a magnitude that is apparent to the senses.
The atoms of particular elements have the same magnitude (or more precisely the same “smallness”, or lack of magnitude), and the same shape, but they differ one from the other by the number of basic characterists (guna) they possess. Atoms of the element wind have only tangibility, while atoms of earth have the most features. Some earth atoms have odor as their defining characteristic (which, however, is not an essential characteristic). Furthermore, atoms differ not only in the place an atom occupies, but in the identifying differentiation they possess which individualizes them and enables God and yogis to recognize them even when they change place without being observed.
Characteristics of atoms the element earth: color, odor, taste, etc., may be changed by “cooking” (paka), that is, by contact with the element fire. The process of sensory qualities changing into composite substances consists in the disintegration of a substance into atoms, “baking” new qualities (e.g., another color) in the atoms, and rearranging the atoms into a form that approximately corresponds to the original substance. All this happens in a few moments (ksana).
Intermediate substances built of atoms are divided into bodies (the seats of souls and minds), senses (situated in definite parts of the body, and obtaining knowledge by contact with a similar object), and objects. Only the sense of hearing (like the pervasive element akashi that corresponds to it) does not have an atomic structure, but is a portion of the ether that knows its object and is limited by the organ of hearing.
Souls (atman) are all-pervasive, but each soul possesses its own individual mind (manas) for contact with the world. This individual mind is of atomic size and thereby at the speed of lightning spans the distance between the senses in the body and transmits information to the soul.
H. Ui, The Vaiśesika Philosophy, C 1917, Benares 19622; The Vaiśesika—system, A 1918, Wie 1969; S. Radhakrishnan, Indian Philosophy, Lo 1951 (Filozofia indyjska [Indian philosophy], I–II, Wwa 1959–1969); F. Frauwallner, Geschichte der indischen Philosophie, Sa 1953 (Historia filozofii indyjskiej [History of Indian philosophy], I–II, Wwa 1990); K. Potter, Encyclopedia of Indian Philosophies, I: Bibliography–Delhi 1970, 19832; 19863, II: Nyaya- Vaiśesika up to Gangeśa, Delhi 1971, Pri 19782; http://www.faculty.washington.edu/kpotter; F. Tokarz, Z filozofii indyjskiej kwestie wybrane [Selected questions from Indian philosophy], II, Lb 1985.
Maciej St. Zięba
LOGICAL ATOMISM. Logical atomism is a group of views in ontology, epistemology, and the philosophy of language.
Logical atomism began at the beginning of the twentieth century under the influence of formal logic, which was growing intensely at the time. According to logical atomism, formal logic describes the basic structure of being, knowledge, and language. Some scholars see the first appearance of this view in the monadology of Leibniz. The term logical atomism was introduced by B. Russell to describe his own views after the year 1898. However, the term seems to be more properly used to define the position of L. Wittgenstein as it took its final form in the Tractatus Logico-Philosophicus, and Russell’s position in the period from 1905 to 1924. According to Russell, logical atoms are the ultimate simple subjects of predication, and logical techniques allow us to construct complex objects from them.
The discovery of mathematical logic and its standard form published in the Principia Mathematica inspired Wittgenstein and Russell to create a philosophical position that holds that in being, cognition, and language exists a structure similar to the structure of mathematical logic. Therefore they accept the existence of simple objects described in atomic propositions, and that all the other elements can be constructed univocally from simple elements with the help of the functors of mathematical logic.
In the Tractatus, Wittgensteain only provided an outline of the position and admitted a great number of very detailed interpretations of logical atomism. The structure of the world is derived from the structure of language that serves to describe the world. Every proposition of language can be presented in the form of a combination of atomic propositions describing simple states of affairs. Any particular atomic proposition can receive only one of two logical values: a simple state of affairs exists insofar the atomic proposition that describes it is true, and it does not exist when the atomic sentence that describes it is false.
Wittgenstein did not show what simple states of affairs are, but stopped at specifying certain conditions that simple states of affairs must meet. A simple state of affairs is structurally isomorphic with the atomic proposition that describes it, and this atomic proposition is composed of a system of names whose meanings are simple objects. A simple state of affairs therefore is a system of named objects that corresponds to a system of names in an atomic proposition. Atomic propositions are logically independent, i.e., the logical value assigned to one of these propositions has no influence on the logical value of any other atomic propositions. Thereby it may be recognized that the assignment of particular logical values to all atomic sentences univocally describes a certain possible world where all complex states of affairs can be constructed of atomic propositions with the help of logical functors under the condition that all atomic propositions have a definite logical value.
According to Wittgenstein’s principle of extensionality, every proposition of ordinary language has a univocal translation in the form of a combination of atomic propositions joined by logical functors. Some of these complex propositions are true (e.g., p ∨ ~p) or false (e.g., p ∧ ~p) regardless of the manner in which logical values are assigned to the component atomic propositions. They are described respectively as tautologies and contra-tautologies.
Ordinary language has a form that leads us into error since it suggests to us that the names that occur in it, e.g., “tree” are the names of simple objects, which is untrue. Wittgenstein tried to argue for the existence of more complex objects by using a reductio ad absurdum argumentation. Let us suppose that there exist atomic propositions that describe complex objects, e.g., “Under the tree a car is parked”. If we consider a possible world in which there are no cars, the above proposition is untrue. Yet we cannot ascribe falsehood to it, since if we treat this proposition as atomic, it describes a certain system of objects and is false when the system of objects is other than described. It does not contain in its meaning a condition defining that it is false when one of the described objects does not exist. Since we cannot ascribe to this proposition a logical value that is in disagreement with the accepted principle that every proposition has a definite logical value, we must admit that the simple objects described by atomic propositions exist.
Russell thought of his own logical atomism as opposed to F. H. Bradley’s idealistic monism. Russell’s works that are recognized as showing his acceptance of logical atomism are On Denoting (1905) and Logical Atomism (1924). The first work provides the beginning of a theory of incomplete symbols, including a theory of description. Consequently the ontological engagement of any particular theory may be reduced by reformulating it. In this reformulation expressions leading to problematic ontological suppositions are eliminated, especially suppositions concerning the existence of beings that can be constructed logically.
The theory of incomplete symbols also has an important epistemological consequence as it show how knowledge of a broader range of objects may be obtained by knowledge of a much smaller range of objects. Russell recognized as epistemologically fundamental the objects that we know by way of immediate acquaintance. We obtain knowledge of the other objects by description. Description is always dependent upon knowledge through acquaintance.
Atomic propositions are composed of simple symbols: proper names and predicates. Simple objects are the meaning of simple symbols (Russell’s logical atoms). The simple objects are marked by the fact that an understanding of them may be reduced to a direct acquaintance with them. Russell held that we cannot possess an immediate acquaintance of a thing (e.g., a table), but only sense data (e.g., visual experience of a rectangular block of color, or a tactile impression of a hard and smooth surface). Atomic propositions therefore contain proper names that replace sense data, and predicates that replace properties and relations of sense data.
An atomic fact corresponds to every atomic proposition. The atomic fact contains the meanings of the simple symbols that occur in the proposition and thereby is the criterium for its logical value. Besides atomic facts, which are sense data containing certain properties and relations, Russell distinguished, in a spirit of Platonic idealism, negative facts and general facts that correspond to general propositions.
On the foundation of logical atomism in the ontological and epistemological version, Russell also developed atomism in the theory of meaning. Our understanding of a proposition consists in direct acquaintance with the component meanings of which the meaning of the proposition is composed. Therefore every non-atomic proposition must be analyzed in the categories of atomic propositions of which we possess immediate knowledge. This analysis also indicates the proper way to understand a particular proposition, which is particularly important in the case of the propositions of ordinary language. Such propositions have a “superficial” form that suggest, for example, that the term “table” is a description of a simple object and not of a logical construction composed of sense data. This “superficial” form turns out to be a false indicator of the semantic individuals that in fact create a given proposition.
Sense data, their properties and relations are not only the basic semantic individuals, but they are also the ultimate components of reality. The epistemological predominance of the logical reduction of objects known to us from daily experience to logical constructions from sense data is that the latter are are ultimately accessible to us in direct acquaintance, and therefore they are very certain.
There is a widespread belief that Russell’s program in all its implications was realized by Carnap in Der logische Aufbau der Welt. Carnap made a detailed logical construction of the objects of daily experience from sense data, but he followed completely different epistemological principles.
Wittgenstein presented many arguments against logical atomism, e.g., that argument from the impossibility of a private language, or indicating that atomic propositions as Russell understood them are logically dependent.
The semantics of possible worlds, which Wittgenstein accepted by way of Carnap, and the verificationist criterium in theories of meaning, are the most lasting influences of logical atomism in contemporary philosophy.
B. Russell, On Denoting, Mind 14 (1905), 479–493; B. Russell, A. N. Whitehead, Principia Mathematica, I–III, Lo 1910–1913, 19502; B. Russell, Knowledge by Acquaintance and Knowledge by Description, Proceedings of the Aristotelian Society 11 (1911), 108–128; idem, Our Knowledge of the External World, Lo 1914; idem, The Philosophy of Logical Atomism, Monist 28 (1918), 495–527; 29 (1919), 32–63; L. Wittgenstein, Tractatus Logico- Philosophicus, Lo 1922 (Wwa 1968,19972); B. Russell, Logical Atomism in: Contemporary British Philosophers, Lo 1924, 356–383; R. Carnap, Der logische Aufbau der Welt, B 1928, H 19744; J. P. Griffin, Wittgensteain’s Logical Atomism, Ox 1964; D. F. Pears, Bertrand Russell and the British Tradition in Philosophy, Lo 1967, 19722; W. Lycan, Logical Atomism and Ontological Atoms, Synthese 46 (1981), 207–229; Rereading Russell. Essays in Bertrand Russell’s Metaphysics and Epistemology, Minneapolis 1989.