Philosophy and Ideology. Z. A. Jordan 1963
From the moment he began teaching philosophy at Warsaw University in 1918 Tadeusz Kotarbiński has been the most influential philosopher in Poland. Kotarbiński’s intellectual leadership has been enhanced by the moral authority which he commands and which is not limited to the academic circles.
Kotarbiński’s starting point was ‘philosophical minimalism’: the relinquishing of the consideration of great philosophical issues in order that basic philosophical concepts might be clarified and defined and scientific habits of mind firmly established. Philosophy has no methods other than those used in the deductive and empirical sciences. In a certain sense, there are even no philosophical problems. What is called ‘philosophy’ is a composite whole consisting of disparate, unrelated parts: psychology, logic, the theory of knowledge, methodology, ethics, aesthetics, metaphysics, philosophy of history and of Nature, sociology. It is better to give up the term ‘philosophy’ altogether. Specialisation is a prerequisite of making philosophy a scientific discipline. The subject which Kotarbiński has chosen for himself and in which he excels is logic, the theory of knowledge and methodology. ‘Logic’ in this context means ‘modern formal logic’, which Kotarbiński accepted as a model of precision and applied in his inquiry in the elucidation of concepts and problems selected as his particular concern.
However, Kotarbiński soon left the narrow limits which he set for himself and others. In a number of essays published between 1920 and 1935 and in Elements of the Theory of Knowledge, Formal Logic and Methodology of Science – perhaps the most widely read and the most important philosophical book of the period between the two wars – he examined various problems of the philosophy of language, logic, methodology, physics, psychology, and the humanities from the viewpoint called by him ‘reism’ and later ‘concretism’. In its inception reism was a semantical doctrine intended to help in the elimination of pseudoproblems and in the formulation of the real ones in a clear, precise and materially valid manner. In the course of time the volume of research on various special problems, undertaken by means of semantical analysis, made of Kotarbiński a system builder. The main characteristics of his system are nominalism and materialism. While nominalism is an essential part of reism conceived as a semantical doctrine, materialism is not. As Kotarbiński himself later discovered, there were reists before him. One of them was Leibniz and another was Brentano; the latter was a dualist and the former a spiritualist. Those in Poland who supported reism were not always materialists, just as all materialists were not reists.
The shortest and most precise way of describing semantical reism is to say that it provides a philosophical interpretation of the only axiom of Leśniewski’s ontology. This axiom states the necessary and sufficient conditions for the function ‘x ∈ y’, in which ‘∈’ stands for ‘is’ in its main existential meaning, to be true. These conditions may be interpreted to mean that a singular proposition is true only if its subject is a genuine non-empty name. But the question, which names are genuine and non-empty and which are not is an extra-logical question, and reism is a semantical answer to it.
The thesis of semantical reism states that only names of concrete objects, either corporeal or sentient, are genuine names. All the others are apparent or quasi names. For instance the name of a relation is an apparent, objectless name, and it cannot function as subject in a sentence implying the consequence that a certain object is a relation. If the sentence: ‘the relation of being a spouse is symmetrical’ (R) is considered to be a substitution of the function ‘x ∈ y’, in which the functor ‘∈’ carries its main meaning, the sentence (R) is false. We often use, however, the sentence (R) as some kind of shorthand expression, which stated fully would say: ‘for all A and B: if A is a spouse of B, then B is a spouse of A’. This sentence contains no apparent names and is a meaningful and true statement. As it stands, a shorthand expression is neither true nor false. Its truth or falsehood can be ascertained only upon its being translated into a sentence which contains only genuine, non-empty names or variables admitting these and only these names as their value.
What has been explained on the example of the category of relations applies equally to other categories. ‘Properties’, ‘events’, ‘facts’, ‘meanings’, ‘propositions’, ‘classes’, are apparent, objectless names and sentences which imply the existence of properties, events, facts, meanings, propositions, and classes are meaningful but false, unless they are considered to be shorthand expressions. Shorthand expressions must be translated and reduced to their ‘normal form’ before they can be stated to be true or false. A reistic analysis of language consists in the examination of expressions which seemingly have a correct syntactical structure, but literally understood are misleading and false; in finding their semantically correct translation, which will enable us to see what problem they involve, what solution there might be, and whether they are true or false. In this manner also pseudo-problems can be eliminated and new problems revealed.
A reistic analysis of language was demonstrated in Elements of the Theory of Knowledge, Formal Logic and Methodology of Science on a variety of problems, including those concerning the concepts of time, space, mind, matter, as well as the concepts encountered in the humanistic studies and historical sciences. Its publication aroused many controversies and it was from that moment that reism acquired the character of a full-fledged philosophical doctrine.
The semantical doctrine of reism is a method by which all ostensible references to abstract entities can be shown either to be meaningless or reducible to expressions which imply or assume the existence only of concrete objects. This is the nominalistic programme in its modern form, initiated in the Anglo-Saxon world by Quine in 1940. Nominalism as an assumption of the philosophy of science is the view that the only values for variables admissible in the language of science are to be concrete objects or individuals, that is, entities of the lowest type in the sense of the simplified theory of types, which, of course, does not exclude using general terms in this language. Semantical reism does not say anything about these concrete objects. To say what these objects are, we have to leave the ground of semantics and go into that of ontology.
The ontological doctrine of reism is also called ‘somatism’. The main thesis of somatism states: ‘every object is a thing’. ‘Thing’ is a defined term and means ‘a physical or sentient body’ (in the non-exclusive meaning of ‘or’). ‘Physical’ can be further analysed. ‘Physical’ in Kotarbiński’s sense means the same as ‘temporal, spatial, and resistent’. The term can be thus applied both to solids in the meaning of common sense physics, to an aggregate of such solids, to particular parts of solid bodies, and to something that is not solid in the popular sense, for instance, to an electro-magnetic field. ‘Sentient’ is not further analysed. ‘A sentient body’ designates animals, men, and also what is referred to by the term ‘soul’ or ‘mind’. The thesis of somatism entails the thesis of pansomatism: ‘every soul is a body’. Pansomatism does not prejudge whether the soul is identical with the whole organism or with one of its parts. It only holds firmly to the statement that if something is a soul, this something is a body or part of it. On the strength of pansomatism we can say there are only bodies in the Universe.
Somatism (ontological reism) has been described as materialism without matter; to formulate its assumptions it does not use the concept of matter at all. This was probably prompted by the consideration that the term ‘matter’ cannot be assumed as a primitive term, that it would have to be explained and defined. But this would require analysing the concept of matter and this concept belongs to physics and not to philosophy. It was not possible to take it over from physics, because the physical concept of matter was made vague by modern discoveries; it was not clear either how the physical concept of matter could be applied to sentient bodies.
These considerations also explain other peculiar features of somatism which is a materialistic doctrine in a certain sense of this term, and not in another. Somatism is clearly a monistic materialism; it implies that the statement: ‘no soul is a body’, is false. It is not a materialistic doctrine, if materialism is understood to mean: ‘psychical phenomena are physical phenomena’ or ‘mind is merely the highest product of matter’. In its literal meaning the former statement is false – no object is a phenomenon whether psychical or physical – and in another, to be explicated from this abbreviated statement-like expression, it is again a scientific and not a philosophical question. The latter statement does not necessarily follow from the thesis of somatism. Other possibilities are left open and a supporter of somatism will wait for the verdict of science on this matter.
The same applies to the mechanistic or dialectic hypotheses, with either of which materialism is usually closely associated. A supporter of ontological reism is committed to neither of these hypotheses. The first of them would imply that man is a machine, and experience does not show man to be a machine; the second is a reaction to naive myths about the creation of the world and to Hegel’s idealistic historiosophy, of which it did not manage entirely to free itself. In the theory of knowledge reism leads to the view called ‘radical realism’, which is very similar to that of sensational realism. Sentences with the names of sense-data or elements (in Mach’s sense) as subjects are either false or nonsensical. Such sentences are false, because no object is a sense-datum, an element or a complex of elements. A radical realist considers critical realism, phenomenalism or naive realism as a learned speculation which does not stand the test of semantical analysis. He is inclined to recognise that things he perceives may be rough or soft, sweet or bitter, white or black, in the same way as they are spatial and temporal. He is, therefore, close to the commonsense view that ascribes the primary and secondary qualities to the physical objects. What he affirms about the objects directly observed, is not necessarily truly affirmed.
There is a difficulty here – that of criteria which allow to distinguish a true empirical statement from a false one – but this difficulty is common to all possible theories.
Radical realism presupposes the reistic interpretation of psychological statements. To put it in the briefest form possible, the latter claims that all psychological statements are reducible to the schema: ‘A experiences this: P’, where ‘A’ is a name variable and ‘P’ is a variable admitting as substitutes any expression that refers to bodies of the outside world, including the body designated by A. Every psychological statement is based on extraspection, and never on introspection. What we call ‘introspection’ is in fact and on closer examination, a perception, an experience stimulated either by external or internal senses. The latter is the case when ‘P’ stands for an enunciation referring to the body of A.
Applied to various kinds of psychological statements, in particular to those in which what A experiences refers to other people’s experiences (other minds), the reistic interpretation of psychological statements meets serious difficulties. These are linguistic and extra-linguistic, resulting either from the complexities involved in the translation of psychological statements into the reistic language or from the peculiarities of what for the sake of brevity is referred to as psychological phenomena. The former difficulties become also very apparent when reism is applied to praxeology, the theory of effective action, to which Kotarbiński has devoted much time and attention.
Kotarbiński has also a pronounced interest in ethics. One of his first publications was a critical study on utilitarianism in John Stuart Mill’s and Spencer’s ethics. Later other philosophical questions somehow outweighed this interest and only after the Second World War he returned to it to defend the individualistic conception of morals without religion and sanctions. Although he was influential also in this respect, he did not evolve any theory of morals and was content with the elucidation of concepts and with the disentangling of moral issues involved in social problems. He surveyed them with the zest of a social reformer, supported by the impartiality and serene detachment of a philosopher free from irrelevant prejudices, anxious to understand human nature, and deeply concerned with the dignity of man. He has lived in accordance with his views and convictions, showing forebearance to others and making high claims on himself. This has made him not only a mind respected for its achievements, but also a man loved by everyone who came in contact with him.
Ajdukiewicz has kept closer to the minimalistic programme in philosophy than Kotarbiński. His main object of interest has been logic and methodology to which later the theory of knowledge has been added. It is very difficult to summarise his writings and still more difficult to say in general terms what his views are. He is at his best as the painstaking analyst of a specific issue, which he takes great trouble to formulate and which is followed by a closely reasoned argument intended to elucidate the issue involved and to clarify the terms in its formulation. Being a philosophers’ philosopher, he is a model of clarity and precision as a teacher. He is the author of many textbooks which are among the best written in Poland. He put into these textbooks much that he had learnt from others as well as what he had found himself without claiming the credit for what was new in them.
His main contributions to the development of philosophy in Poland in the period between the two wars can perhaps be summed up as follows. He was a trenchant critic of the nominalistic programme, which gained him the reputation, not entirely unjustifiable, of being a Platonist. He formulated the view known as ‘radical conventionalism’. Having become converted to realism in the theory of knowledge – at the time of writing his essays on radical conventionalism he was, as he himself stated later, at the cross-roads of epistemological idealism and realism – he applied semantical concepts in the examination of the idealist argument, which contributed to the elucidation of the idealist paradox and initiated new methods in the examination of the problems of the theory of knowledge in general.
Radical conventionalism was the most widely known and the most spectacular of Ajdukiewicz’s contributions. Poincaré contended that some empirical problems are insoluble unless some principles, which experience can neither prove nor disprove and which are neither true nor false, are accepted. Ajdukiewicz went a step further. According to him, all propositions accepted by us and constituting our ‘view of the world’ are not unequivocally determined by the data of experience, but also depend on the choice of language and its universe of meanings (Begriffsapparatur), in terms of which our ‘view of the world’ is formulated. This happens in a language, which is closed and connected. In such a language, to put it briefly but imprecisely, everything can be said in an unequivocal manner and everything said is somehow determined by any other valid statement of this language.
A closed and connected language is clearly modelled on an ideal language of the formalist philosophers, like Carnap. It is not, however, an artificial language, since its structure cannot be specified solely in terms of its syntax. The empirical rules of meaning introduce sentences whose assertibility depends on extralinguistic reality. Such a language is an essentially open language and it is hard to imagine how it could ever be connected. Ajdukiewicz soon realised that his closed and connected language was not a discovery but an invention; no natural or artificial language, as rich as his, could ever fulfil the requirements imposed upon it. He gave it up and overboard with it went the thesis of radical conventionalism. Without at least two untranslatable closed and connected languages, the thesis of radical conventionalism becomes groundless.
Although the idea of a closed and connected language turned out to be a fiction, it was an important contribution to the development of philosophy in Poland. At the source of Ajdukiewicz’s examination stand some of Tarski’s results, in particular those concerning the difficulties of providing an adequate and formally correct definition of a true statement in ordinary language. Consequently, Ajdukiewicz did not use the concept of truth and introduced only a rule of meaning which governs the use of the term ‘true’. This rule does not belong either to logical syntax or to logical semantics, but to what later Ch. W. Morris called ‘logical pragmatics’. This rule lays down that if a sentence p of the language L is an assertable sentence with respect to the rules of meaning of the language L, the user of the language L will accept also the statement: ‘’p’ is true’. Although the concept of truth in the sense of logical pragmatics was not meant to replace the semantical concept of truth (in this sense radical conventionalism does not entail the relativism of truth), the limited usefulness of the former puts into relief the importance of the latter. The definition of the concept of truth in terms of logical pragmatics reinforced the realisation that the use of the predicate ‘true’ is not determined solely by the rules of meaning of the language in which it is applied. More generally, philosophical questions are partly of a linguistic and partly of an extra-linguistic nature. For Ajdukiewicz himself this was the starting point for the examination of the idealist position in the theory of knowledge, in which a true proposition is defined as a proposition determined by the rules of meaning. Ajdukiewicz’s first contribution can be, therefore, described as the strengthening of the realistic and anti-linguistic trend, if by the latter is understood the reaction against the reduction of philosophical problems to purely linguistic questions. This can be seen, for instance, in Kokoszyńska paper Syntax, Semantik und Wissenschaftslogik, in which she criticised Carnap’s views on language and his reduction of philosophy to logic of science. Her criticism was based on Tarski’s contributions to the philosophy of language and on the consequences to be drawn from Ajdukiewicz’s investigations, which put into relief the importance of semantical and pragmatical rules for a unique characterisation of a language.
Ajdukiewicz also contributed to the realisation that the meaning of an expression is relative to the language in which it occurs not only in the obvious and trivial manner, but also in the sense that the meanings of expressions of a language constitute a structure determined by interrelated rules of meaning. Ajdukiewicz attaches great importance to his differentiation of these rules (axiomatic, deductive, empirical), but this seems to be less important than the above mentioned more general fact. His insistence that language has a structure and that this structure is not exclusively formal or syntactical (for people speaking a language with the same syntax but different meaning rules would not understand each other) turned out to be fruitful. It contained the ideas from which logical pragmatics and the conception of semiotic as an instrument of philosophical inquiry were evolved.
Like other conventionalists before him, Poincaré in particular, Ajdukiewicz was impressed by two strangely contrasting facts: the ‘porosity’ and inadequacy of everyday language and the effective use to which language can be put by a logician or a scientist. This suggested that the search for the necessary conditions of mutual understanding – of which scientific language provides a striking example – and the elucidation of the problem of meaning in general cannot be successful unless language is considered as a structure and its structural features, formal and informal, are investigated. The view that language has a structure of its own again emphasised the importance of the linguistic aspect of philosophical problems and provided this belief, novel at that time, with a rational explanation.
Finally, very much worth emphasising is Ajdukiewicz’s effort to provide a definition of meaning which does not use the concept of designation or reference. There were three reasons which prompted Ajdukiewicz to undertake this course. One has been already mentioned – the danger of antinomies resulting from using semantical concepts in semantically closed languages. The second was the observation that all terms and expressions of a language have a meaning, but not all of them designate something, and that two expressions with different meanings, e.g. ‘the highest peak in Europe’ and ‘the highest peak in Switzerland’, might denote the same object. The third was the controversy with Kotarbiński about universals and Ajdukiewicz’s critical evaluation of the reistic assumption, held in common with logical atomism, that the concept of meaning is closely bound with that of designation. Furthermore, Ajdukiewicz rejected the view, held by logical positivists, that the vocabulary and logical syntax are sufficient to characterise a language and provide a basis for definition of meaning associated with the expressions of this language. He discovered the missing factor in the conditions under which an expression has a definite meaning, the correlation between the conditions and expressions being made explicit in empirical meaning-giving rules, the way the expressions are used and asserted, which is the basic concept of logical pragmatics. We shall return to Ajdukiewicz’s theory of meaning in Part III.
Zawirski was a philosopher of great versatility. He moved with ease over the fields of logic, mathematics, physics, philosophy and combined historical with systematic interests. He has done much to keep philosophers in Poland familiar with the latest developments in mathematical logic, mathematics and physics and its philosophical implications. There was a streak of the metaphysician in him in the sense that he was attracted by wide conceptions and generalisations, for which no adequate empirical support could be given, but which fill in the gaps in our knowledge of the world and make it intelligible. He seemed to have been worried by what useful purpose philosophy might serve if it does not provide us with a Weltanschauung. On the other hand he was fully aware of what happens when speculations are given free rein. His apprenticeship in the Lwów school and his training in science had the upper hand, but he sympathised with the tendency to extend the scope of philosophical thought instead of restricting it to the minimalistic programme.
When the sharp distinction between a metaphysical assertion and a scientific statement, made by the Vienna Circle, broke down, Zawirski felt that perhaps metaphysics could be revived as a hypothetical-deductive discipline, to which the axiomatic method should be applied. This metaphysics presupposed as much knowledge of mathematics and natural science as he himself possessed. The man who tries his hand at metaphysics should be able to examine the relation between the calculus of probability and many-valued logics; to say in what way intuitionistic mathematics differs from classical mathematics; and to analyse the dispute of determinism and indeterminism in atomic physics.
These subjects were mentioned on purpose, because these and similar questions were discussed by Zawirski in his publications. He was, above all, a philosopher of science and he exemplified the interest in the theory and methodology of science, which was one of the characteristic features of the Warsaw school. Outside Poland he will perhaps be remembered as a historian of scientific concepts. His book in French on the evolution of the notion of time was his greatest work and probably his most valuable contribution to science.
In the period between the two wars Czeżowski incarnated all the characteristics of the Warsaw school. He avoided problems which could not be precisely formulated or examined by exact methods. His papers were mostly concerned with specific problems of traditional formal logic. Although he was free from any taint of psychologism, he retained a lasting interest in some psychological questions. He showed an increasing appreciation for the historical and evolutionary approach to philosophical concepts and to scientific methods.
This has become very marked since the war; his historical interests have considerably widened to include the history of logic. The war has affected him also in other respects. While he pays as much attention as ever to the strict rigours of the philosophical craftsmanship and practises them, as in the past, in short papers dealing with specific questions of inductive logic, probability reasoning, theory of science and its relation to philosophy, he no longer excludes problems in which the same standards of precision cannot be achieved.
Adam Wiegner (born 1889) had no connections with the Lwów school. His first contribution dealt with Leonard Nelson’s important and little known examination of the problems of knowledge. Wiegner’s main interests were, however, logic and methodological problems of psychology. He published an important little book concerned with an analytical definition of psychological phenomena in which he examined a number of fundamental psychological concepts, such as those of introspection, of psycho-physiological isomorphism, and of behaviour. He continued this line of investigations with a paper on the philosophical significance of the Gestalt psychology. He has published little but as a teacher he exercised a beneficial influence.
The role and importance of the Warsaw school cannot be judged alone by the achievements of its most prominent representatives. Also outside the school there were thinkers whose contribution to the development of philosophy in and outside Poland was considerable. The importance of the Warsaw school should be measured by its contribution to the intellectual life of the country and by the influence it exercised on the development of philosophy. In this respect it had no rivals. Practically everybody came under its spell and influence. The conception of philosophy, of its subject-matter, task, and method, the standards of philosophical thinking established by the leading exponents of the Warsaw school have been universally accepted. Although the school existed without interruption for less than twenty years, there emerged a living tradition, oral and written, which has turned out to be an intellectual force, with a considerable power of resistance and of attraction, that survived the test of historical catastrophies and upheavals.
irm and settled but as a teacher he has emulated Twardowski in liberalism and tolerance. Among his pupils were logicians – Alfred Tarski, Bolesław Sobociński, and Henryk Hiż; psychologists – Walter Auerbach, Irena Filozofówna, Edward Geblewicz and Estera Markin; philosophers of law – Rafal Wundheiler; historians of modern thought Mieczysław Milbrandt (1915-1944), Antoni Pański and Jakub Rajgrodzki; physicists – Aleksander Wundheiler; those who were to make their names in the philosophy and history of art – Mieczysław Wallis, sociology – Aleksander Hertz and Stanislaw Ossowski, and the science of morals – Maria Ossowska. There was a group of influential methodologists – Janina Hosiasson-Lindenbaum (1899-1942), Janina Kotarbińska and Edward Poznański. All of them in the particular field of his or her interest tried to practise and to improve the methods learnt in the period of their apprenticeship in the Warsaw school. There was finally J. F. Drewnowski (born 1901), who became one of the moving spirits behind the initiative of transplanting modern formal logic to Thomism .
Ajdukiewicz’s pupils excelled in the methodology and the theory of science. They included Izydora Dąmbska, Maria Kokoszyńska, Seweryna ŁuszczewskaRomahnowa, Henryk Mehlberg and Zygmunt Schmierer. From Wilno came Jan Rutski who under Czeżowski’s guidance made his way from law to philosophy.
Some of these names do not now need any introduction even outside Poland. Hosiasson-Lindenbaum’s contributions on induction and probability, KokoSzyńska’s on the concept of truth, Mehlberg’s on the epistemological problems of physics are known to those interested in these particular subjects. Of the achievements of some of the others, especially of Ossowski and Ossowska, we shall speak again in discussing the course of events in the post-war period.
For a description of the Warsaw school in a general manner only methodological terms are appropriate. From whatever viewpoint it is considered, one cannot find a body of beliefs, substantial enough and held in common, that would justify calling it a school of thought in the traditional meaning of this term. Semantical reism is closely associated with the nominalistic programme, with realism in the theory of knowledge, and materialism in ontology. But reism was not the creed of the school, it was supported by some of its members and criticised by others. Those who adopted semantical reism did not always combine it with materialistic views or feel committed to the nominalistic programme. While the view that philosophical problems are partly a question of language was widely held, nobody ever went to the length of supporting the opinions of the Vienna Circle. Indeed the main thesis of the Wiener Kreis that all meaningful philosophical problems belong to logical syntax, was criticised sympathetically but firmly on semantical and other grounds, and this criticism proved to be justified. It was agreed in Poland that in philosophy there may occur what Carnap called pseudo-object questions, which because of their formulation seem to refer to extra-linguistic reality while in fact they refer to the object-language and should be considered as logical or syntactical problems. But the view that all questions of philosophy can be shown to be syntactical was firmly rejected. Problems of ethics, and, in general, those concerned with values and norms, were never altogether banished as unscientific. The boundary lines which divided scientific from unscientific questions in philosophy were much more determined by the manner of the procedure than by the substance of the problems involved. There was, therefore, no finality about these boundary lines. It was felt that this was a reasonable attitude and one in keeping with the requirements of scientific progress. There is a body of beliefs held in common at every stage of scientific development which are surrounded by some kind of no man’s land where what is true for one person is not necessarily true for another. The former makes for the consolidation of the knowledge already acquired, the latter for its further expansion. This applies even more to philosophy. All qualified persons assent to a true scientific statement and only some qualified persons assent to what is held to be a true philosophical statement. The distinction is only too familiar from the history of philosophy.
The views that were held in common were of a very general nature and they thus determined only an attitude to philosophical problems, a method of their solution, and a technique of which this method took advantage. The attitude was anti-irrationalistic, the method scientific (in a sense to be defined), and the technique logistic.
The anti-irrationalistic attitude was prompted by a staunch realism, belief in the absolute conception of truth, concern with and respect for facts, particularly those established by science, demand for clarity and precision of expression. Its negative aspect was a sound and firmly established distrust towards abstract speculations of an illusive simplicity and deceptive clarity and the rejection of any knowledge acquired by other means than those of experience or exact reasoning.
The method was scientific in view of the fact that in the evaluation of philosophical analysis it applied the same criteria of validity as those used in the deductive and empirical sciences. If other sources of knowledge, often claimed by philosophers (intuition or any other kind of direct insight into the essence of things), are discounted, only provable (sensu stricto) propositions and those testable by experience constitute valid knowledge. In principle, the methods of philosophy are those of science. This qualification is necessary in view of the fact that the relation between philosophy and language is closer than between science and language. Since philosophical problems are partly linguistic, this requires not only a greater clarity and precision of expression than is often the case in science, but also calls for an advanced technique in dealing with these partly linguistic and partly factual problems.
The new technique was provided by modern formal logic. Modern formal logic constitutes an unsurpassed model of exact reasoning and an instrument of disentangling involved, complicated and otherwise uncontrollable arguments. It is also the foundation on which new techniques can be worked out. This has been proved over and over again in the distinction between different levels at which our language can operate, and, consequently, between concepts and theorems of different levels; in the examination of language in terms of its syntax, semantics, and logical pragmatics; in the creation of a science of language. Philosophical technique must, therefore, either look to formal logic for guidance, or apply it in practice or study its procedure to improve and evolve better analytical means. Philosophical method cannot be scientific without being logistic.
The methodological unity of the Warsaw school was the result of a long development, to which the logicians, the mathematicians and the philosophers contributed. It took advantage of errors and achievements at home and abroad; it could not have become what it was in a vacuum, without keeping in close touch with what was happening in the world outside. The influence of the great thinkers of the past, of Leibniz, Hume, Mill and Bolzano, of those closer in time or contemporary – Frege, Schröder, Brentano, Poincaré, Duhem, Husserl, Hilbert, Einstein, Russell, Whitehead, Bridgman, Weyl, Neurath, Carnap, Popper, and many others, was considerable. The purpose of this survey is not, however, to trace these influences, but to describe the final outcome of outside impact and local genius.