"Logical Atomism" by Bertrand Russell,1959

Russell's logical atomism had significant influence on the development of philosophy, especially in the first half of the 20th century. Nowhere is Russell's influence more clearly seen than in the work of his pupil Ludwig Wittgenstein. Wittgenstein's Tractatus Logico-Philosophicus appeared in 1921; in it, Wittgenstein presented in some detail a logical atomist metaphysics. (It should be noted, however, that there is significant controversy over whether, in the end, Wittgenstein himself meant to endorse this metaphysics.) In the Tractatus, the world is described as consisting of facts. The simplest facts, which Wittgenstein called “Sachverhalte”, translated either as “states of affairs” or “atomic facts”, are thought of as conglomerations of objects combined with a definite structure. The objects making up these atomic basics were described as absolutely simple. Elementary propositions are propositions whose truth depends entirely on the presence of an atomic fact, and other propositions have a determinate and unique analysis in which they can construed as built up from elementary propositions in truth-functional ways.

Partly owing to Wittgenstein's influence, partly directly, Russell's logical atomism had significant influence on the works of the logical positivist tradition, as exemplified in the works of Carnap, Waismann, Hempel and Ayer. This tradition usually disavowed metaphysical principles, but methodologically their philosophies owed much to Russell's approach. Carnap, for example, described philosophy as taking the form of providing “the logical analysis of the language of science” (Carnap 1934, 61). This originally took on the form of attempting to show that all meaningful scientific discourse could be analyzed in terms of logical combinations beginning with “protocol sentences”, or sentences directly confirmable or disconfirmable by experience. This notion of a “protocol sentence” in this tradition was originally modeled after Russellian and Wittgensteinian atomic propositions. The notion of a “logical construction” was also important for how such thinkers conceived of the nature of ordinary objects (see, e.g., Ayer 1952, chap. 3). The view that scientific language could readily and easily be analyzed directly in terms of observables gradually gave way to more holistic views, such as Quine's (see, e.g. Quine 1951), in which it is claimed that it is only a body of scientific theories that can be compared to experience, and not isolated sentences. However, even in later works growing out of this tradition, the influence of Russell can be felt.

Besides positive influence, many trends in 20th century philosophy can be best understood largely as a reaction to Russell's atomistic philosophy. Ironically, nowhere is this more true than in the later writings of Wittgenstein, especially his Philosophical Investigations (1953). Among other things, Wittgenstein there called into question whether a single, unequivocal notion of simplicity or a final state of analysis can be found (e.g., secs. 46–49, 91), and questioned the utility of an ideal language (sec. 81). Wittgenstein also called into question whether, in those cases in which analysis is possible, the results really give us what was meant at the start: “does someone who says that the broom is in the corner really mean: the broomstick is there, and so is the brush, and the broomstick is fixed in the brush?” (sec. 60). Much of the work of the so-called “ordinary language” school of philosophy centered in Oxford in the 1940s and 1950s can also been seen largely as a critical response to views of Russell (see, e.g., Austin 1962, Warnock 1951, Urmson 1956).

Nevertheless, despite the criticisms, many so-called “analytic” philosophers still believe that the notion of analysis has some role to play in philosophical methodology, though there seems to be no consensus regarding precisely what analysis consists in, and to what extent it leads reliably to metaphysically significant results. Debates regarding the nature of simple entities, their interrelations or dependencies between one another, and whether there are any such entities, are still alive and well. Russell's rejection of idealistic monism, and his arguments in favor of a pluralistic universe, have gained almost universal acceptance, with a few exceptions. Abstracting away from Russell's particular examples of proposed analyses in terms of sensible particulars, the general framework of Russell's atomistic picture of the world, which consists of a plurality of entities that have qualities and enter into relations, remains one to which many contemporary philosophers are attracted.

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Bertrand Russell described his philosophy as a kind of “logical atomism”, by which he meant to endorse both a metaphysical view and a certain methodology for doing philosophy. The metaphysical view amounts to the claim that the world consists of a plurality of independently existing things exhibiting qualities and standing in relations. According to logical atomism, all truths are ultimately dependent upon a layer of atomic facts, which consist either of a simple particular exhibiting a quality, or multiple simple particulars standing in a relation. The methodological view recommends a process of analysis, whereby one attempts to define or reconstruct more complex notions or vocabularies in terms of simpler ones. According to Russell, at least early on during his logical atomist phase, such an analysis could eventually result in a language containing only words representing simple particulars, the simple properties and relations thereof, and logical constants, which, despite this limited vocabulary, could adequately capture all truths.