From the ALWS archives: A selection of papers from the International Wittgenstein Symposia in Kirchberg am Wechsel

1. The Intellectual Honey-moon of Russell and Wittgenstein and its End

After finishing Principia Mathematica in 1910, Russell concentrated his efforts in questions of epistemology. In ”Knowledge by Acquaintance and Knowledge by Description” (1911), and The Problems of Philosophy (written in 1911 but published in 1912), Ch. III, he developed the epistemological implications of his logic in detail. At that time, Russell accepted that whereas we are acquainted with sense-data, we know physical objects by description only. More precisely, we logically infer that there are physical objects from the sense-data we are acquainted with. In 1911 Russell believed that this understanding is much more coherent than any competing philosophy of matter, for example, from solipsism, according to which there are no physical objects at all or from naive realism, according to which we directly apprehend material objects.

Exactly at this point of his work, late in October 1911 Russell met Wittgenstein. Soon between them arose an intellectual sympathy of higher form. On March the 22^d 1912 Russell wrote in a letter: ”His [Wittgenstein’s] attitude justifies all I have hoped about my work. . . . He has even the same similes as I have: a wall, parting him from the truth, which he must pull down somehow.” (Clark 1975, 172)

In fact, in the months between March and November 1912 Russell and Wittgenstein had a Joint Program in philosophy, on which they often worked tête-à-tête, and in which they developed the major tenets of their later works. Incidentally, this was the only time in the history of Wittgenstein’s thought when he worked co-operatively with another philosopher for months. Of course, Wittgenstein often criticised Russell’s conceptions. This criticism, however, was constructive. At that time he tried to advance ideas, supplementary to those of Russell.

Wittgenstein’s visit to Frege in December 1912, by which the latter ”absolutely wiped the floor with [him]”, terminated his intellectual honey-moon with Russell—their Joint Program in philosophy was abandoned. The practical effect was that Wittgenstein decided to leave Cambridge for Norway (which he made in the autumn of 1913)—he didn’t need the collaboration of Russell anymore. The negative effect in theory was Wittgenstein’s criticism of Russell’s Theory of Knowledge (May–June 1913). The first positive result were his ”Notes on Logic”, written down in September 1913.

Despite this criticism, the Joint Program in philosophy from March–November 1912 remained central to the philosophy of both Russell and Wittgenstein. From now on, main occupation of the two philosophers was to develop the already well-charted Program following his idiosyncratic intuition. In what follows, I am going to articulate this Program in view of its later implications for the mature philosophy of both Russell and Wittgenstein.

2. The Impact of the Join Program on Russell and its Effects in Philosophy of Science

Whereas Wittgenstein was a beginner in philosophy, in March 1912 Russell was already an established author. This explains why we are going first to find out the traces of impacts of the Join Program in Russell’s already available philosophy.

This impact had several dimensions. Above all, it was manifested as a kind of sceptical radicalism in Russell, unknown to him before and after that. Most important document of it was his paper ”On Matter” (1912b), written in May–October 1912 but first published in 1992. The declared aim of the paper was: To show ”(i) that all the arguments hitherto alleged by philosophers against matter are fallacious; (ii) That all the arguments hitherto alleged in favour of matter are fallacious; (iii) That, although there may perhaps be reason to suppose that there is matter, yet we can have no means of finding out anything whatever as to its intrinsic nature.” (Russell 1912b, 80) The style used in these lines was perceptibly close with that used by Wittgenstein in his writings from 1912–21.

This sceptical stance led to changes in Russell’s philosophy of science. In ”On Matter”, he abandoned the belief that matter is an inference out of sense-data and accepted that it is a logical construction out of them. The underlying idea of this new understanding was that the world consists of independent units—sense-data, which can be both particulars and universals,—ordered in different, logically organized nets. In these nets the units are logically interrelated to one another. We can infer from the sense-data that there are (hypothetical) material objects. But if physics is to be applied, as for example in calculating the motions of the moon, it must be possible to derive, from the sense-data which we have when we see the moon, some object, either inferred or constructed, which satisfies the hypotheses of abstract physics.” We can advance many such hypotheses in physics which are ”indistinguishable from the standpoint of the pure mathematician, since all give the same formulae, and the difference lies only in the meaning assigned to the symbols” (Russell 1912b, 83, 87).

3. The Joint Program in Logic

Parallel to Russell’s work on the paper ”On Matter”, Wittgenstein did some investigation in philosophy of logic. Indeed, the ”discussion of the problem of matter and of the nature of logic proceeded pari passu” (McGuinness 1988, 160). An evidence for this is the recent discovery, made by B. F. McGuinness, that on the back of ”Matter—the problem stated” (the first MS of ”Nine Short Manuscripts on Matter” (Russell 1912/13), written shortly after Russell delivered ”On Matter” in Cambridge on 25^th of October 1912), Wittgenstein produced jottings on logic in which the idea of truth-table and of the idiosyncratic Tractarian conception of one logical constant were developed for the first time.

In the jottings Wittgenstein advanced the idea that the truth-table is a logical symbol of the propositions under consideration (see Wittgenstein 1976, 177). This means that the truth-possibilities can be expressed employing a single sign for logical connective. Specifically, Wittgenstein discovered that logical constants can be reduced to a single operation: ”?” (in the Tractatus 5.1311 this sign is delivered as ”|”.)

This point hanged together with the already mentioned (in § 2) assumption of Russell’s that the world of science consists of independent units (atoms),—sense-data—ordered in many logical nets, in which the units are interrelated to one another. This is supported by the fact that the sign ”?”, which is to symbolise the interconnectedness of the logical atoms, was sometime used by Russell in the meaning of interweaving of the elements in a complex:¹ they are tied together up—in a certain way.

Later Wittgenstein expressed the connection between the ontological problem of composition of complexes and the assumption that there is only one logical constant thus: ”Wherever there is a compositeness . . . we already have all the logical constants”, and this means that there is a ”sole logical constant.” (Wittgenstein 1922, 5.47) He developed this idea further, setting out that the relations in the Tractarian actual states of affairs and propositions have, in a sense, the same character as the relations between the objects in states of affairs. This means nothing but that formations of different order—(i) objects; (ii) states of affairs; (iii) propositions—are connected in one and the same way: through their elements that are hinged together as the joints of a bulky construction.

Truthless Logic. This idea goes hand in hand with a Joint Program of Russell and Wittgenstein for Truthless Logic. Indeed, between April and October 1912 Russell also worked on logic. The product of this work was his paper ”On Logic”, of two pages only, written immediately after 13 October 1912. Its main thesis was that logic was the study of the logical form of complexes: ”It did not deal with judgements (which are a matter for psychology) nor with propositions (which can be false and hence cannot be anything objective but must be mere forms of words). Complexes will be recognised as identical with the true or asserted propositions.”² (McGuinness 1988, 162)

At that time, this was the position of Wittgenstein as well. He abandoned this doctrine only after he visited Frege in December 1912.

4. Changes in the Project in Logic after Wittgenstein’s Visit to Jena in December 1912

They were made in three directions.

(a) Truth-making. Wittgenstein accepted that the meaning of propositions is not the complexes which correspond to them but propositions’ truth-values (see ibid., 164). More precisely, Frege criticised the identification of complex and fact, accepted in the Joint Program, arguing that ”complex is not like a fact. For I can, e.g., say of a complex that is moves from one place to another, but not of a fact.” (Wittgenstein 1974, 199) Wittgenstein accepted this understanding; after some years of deliberation, Russell accepted it too. Indeed, this was a major change in his ”The Philosophy of Logical Atomism” (1917/18), when we compare it with his Theory of Knowledge (1913), which was based on the logic of complexes.

It is of importance that Wittgenstein connected this conception with the truth-table method developed in his jottings on logic from November 1912, with some modifications, though. Indeed, already in 1912 the truth-table was conceived as a compendium of the possible meanings of the propositions. What was new was the theory of many imaginary possible worlds, only one of which is real. On this understanding, the truth-combinations are nothing but parts of possible worlds; parts of the real world makes some parts of the possible worlds, expressed by the sentences we use, true, or real. This was the theory of truth-making, developed in ”Notes on Logic” (1913) by Wittgenstein (see Wittgenstein 1979, 95),³ and also embraced by Russell some years later in The Philosophy of Logical Atomism (see Russell 1956, 182 ff.).

(b) The Doctrine of Showing. Especially spectacular was Wittgenstein’s criticism in June 1913 of Russell’s multiple-relation theory of judgement. As it was recently convincingly demonstrated, it was based on the doctrine of showing (see Landini 1991). Here it is to be remembered that Russell’s multiple-relation theory of judgement was grounded on the logic of complexes: judgements receive their sense through the logical form of the complex consisting of the judging mind, the individuals judged, and the epistemic relation between them. This understanding was made invalid through Wittgenstein’s criticism. To be sure, ”to Wittgenstein [from after December 1912], logical form is a matter of sense; and ”sense” is captured only when it is shown. . . . There cannot be a theory of logical form” (ibid., 66).

As it is well-known today—from the works of P. T. Geach,—the doctrine of showing was first elaborated by Frege. Apparently, the latter communicated it to Wittgenstein in their discussions in December 1912.

(c) Tractarian Objects. The very idea of a system of objects, out of which the Tractarian world is build up—through the medium of the states of affairs, which are nothing but concatenations of objects,—has its roots in the Joint Program. On this point too the Program was modified. How much?

As already mentioned, in The Problems of Philosophy Russell accepted that sense-data are not to be found in the outer but in the inner world. They are only what we directly perceive. The realm of sense-data comprises colours, sounds, (the private) space, time (see Russell 1912a, 45). They are formed as individuals so that they can be perceived in isolation.

Obviously, in 1912 this was also the view of Wittgenstein. After his reformation through Frege, however, he revised it considerably. In the Tractatus, he accepted that we never know the stuff out of which the sense-data are build. We know them only when they are organized in certain shape, form, size, etc.; but we don’t know them ”in themselves”. Further, he called exactly parts of this rough, non-organize stuff—not the sense-data themselves—objects. This explains the Tractarian statement that objects are colorless (2.0232); they are the substance of the world (2.021).

The objects receive their configuration when they are molded into forms. Before this moment, they were only possible; now they are real. This assumption was a clear step towards a form of ”modal atomism” (Raymond Bradley, Brian Skyrms), apparently suggested by the doctrine of possible worlds, embraced by Wittgenstein after December 1912 (and already mentioned in (a)).

Exactly like the idea of showing and saying, Wittgenstein’s new understanding of sense-data was not assimilated by Russell. This explains why his form of logical atomism differs considerably from that of Wittgenstein.¹