Edmund Gettier is Professor Emeritus at the University of Massachusetts, Amherst. This short piece, published in 1963, seemed to many decisively to refute an otherwise attractive analysis of knowledge. It stimulated a renewed effort, still ongoing, to clarify exactly what knowledge comprises.

How do we know what we "know"? How did we –as individuals and as a society – come to accept certain knowledge as fact? In _Human Knowledge,_ Bertrand Russell questions the reliability of our assumptions on knowledge. This brilliant and controversial work investigates the relationship between ‘individual’ and ‘scientific’ knowledge. First published in 1948, this provocative work contributed significantly to an explosive intellectual discourse that continues to this day.

This collection brings together several essays which have been written between the years 197 5 and 1983. During that period I have been occupied with the attempt to find a satisfactory explicate for the notion of tnithlike ness or verisimilitude. The technical results of this search have partly appeared elsewhere, and I am also working on a systematic presentation of them in a companion volume to this book: Truthlikeness. The essays collected in this book are less formal and more philos (...) ophical: they all explore various aspects of the idea that progress in science is associated with an increase in the truthlikeness of its results. Even though they do not exhaust the problem area of scientific change, together they constitute a step in the direction which I find most promising in the defence of critical scientific realism. * Chapter 1 appeared originally in Finnish as the opening article of a new journal Tiede 2000 - a Finnish counterpart to journals such as Science and Scientific American. This explains its programmatic character. It tries to give a compact answer to the question 'What is science?', and serves therefore as an introduction to the problem area of the later chapters. Chapter 2 is a revised translation of my inaugural lecture for the chair of Theoretical Philosophy in the University of Helsinki on April 8, 1981. It appeared in Finnish inParnasso 31, pp. (shrink)

The modern discussion on the concept of truthlikeness was started in 1960. In his influential Word and Object, W. V. O. Quine argued that Charles Peirce's definition of truth as the limit of inquiry is faulty for the reason that the notion 'nearer than' is only "defined for numbers and not for theories". In his contribution to the 1960 International Congress for Logic, Methodology, and Philosophy of Science at Stan­ ford, Karl Popper defended the opposite view by defining a compara­tive (...) notion of verisimilitude for theories. The concept of verisimilitude was originally introduced by the Ancient sceptics to moderate their radical thesis of the inaccessibility of truth. But soon verisimilitudo, indicating likeness to the truth, was confused with probabilitas, which expresses an opiniotative attitude weaker than full certainty. The idea of truthlikeness fell in disrepute also as a result of the careless, often confused and metaphysically loaded way in which many philosophers used - and still use - such concepts as 'degree of truth', 'approximate truth', 'partial truth', and 'approach to the truth'. Popper's great achievement was his insight that the criticism against truthlikeness - by those who urge that it is meaningless to speak about 'closeness to truth' - is more based on prejudice than argument. (shrink)

The article offers a rigorous explication of the intuitive notion of verisimilitude, I.E., Of the distance of a theory from the truth. The proposal is defended against charges of material inadequacy made by popper, Niniluoto, And miller.

Of two false theories, One can be, Intuitively, Closer to the truth than the other. The purpose of the article is to propose a rigorous explication of this intuitive notion.

2 Popper's Logical Definition of Verisimilitude. 3 Popper's Probabilistic Definition of Verisimilitude. 4 Conclusion.

The Description for this book, The Analysis of Knowing: A Decade of Research, will be forthcoming.

What does it take for one proposition to be closer to the truth than another. In this, the first published monograph on the topic, Oddie develops a comprehensive theory that takes the likeness in truthlikeness seriously.

This paper began with the simple object of finding an account that allowed us to compare incompatible false theories. This we achieved with ρ. But that relation is language — or interest — dependent. ρ' is free from this limitation; though thus liberated it is perhaps rather unconcerned about what is true, and further fails to deliver certain intuitive comparisons. Whether ρ is to be preferred to ρ' or vice versa, seems to me a largely fruitless question: In fact it (...) might be that as we seek to free the idea of verisimilitude from any dependence on language, interests or problems, so we gradually collapse it to nothing more than logical power. (shrink)

There have been many attempts of late to formulate a satisfactory theory of knowledge with which to replace the traditional justified true belief analysis. Almost all agree that it must be the case that in order for S to know that p; i.) p be true, and ii.) S believe that p. Although many argue that there must be a condition stating that S has adequate evidence for p, requirements other than i.) and ii.) are controversial. The most popular approach (...) taken, however, is the addition of a requirement to the effect that for S to know that p there must be no other evidence against p strong enough to undermine S's belief that p, should this evidence come to S's attention. I shall call such a requirement a “defeasibility condition” and any theory containing such a requirement a defeasibility theory.Defeasibility theories are quite effective in handling a certain kind of difficulty to which theories of knowledge are subject, namely problems dealing with what Harman has termed the social aspect of knowledge. (shrink)

When can one say that a new theory is truer than the old one it contradicts, even though neither is absolutely true? We are primarily concerned with the case in which the conflicting theories offer answers to the same questions, and so we do not introduce considerations of "logical width". We propose that part of the new theory is truer than part of the old one when the former part gets right whatever the latter-part got right while the former does (...) not make any new mistakes. Pragmatic considerations will determine the relative importance of whatever new mistakes the new theory does make as a whole. To avoid artificial counterexamples, we restrict the parts compared to those that are "convex". A "convex" theory is one that holds in all cases intermediate between any two cases in which it holds. (shrink)

Russian translation of Gettier E. L. Is Justified True Belief Knowledge? // Analysis, vol. 23, 1963. Translated by Lev Lamberov with kind permission of the author.

Recent interest in the problem of verisimilitude stemmed originally from Popper's desire to provide a non-inductive criterion of merit that will select between two false theories) But the problem has also been taken up by others who are not committed to Popper's anti-inductivism. Indeed Ilkka Niiniluoto has argued that the estimated degree of truthlikeness of a generalisation g which is compatible with evidence e can be equated with the inductive probability of g on e, wherever g is a constituent in (...) Hintikka's sense. It might therefore be worth while to approach the problem afresh, in order to determine quite generally whether a measure of verisimilitude is what is principally needed for the evaluation of scientific progress. I shall argue that it is not. (shrink)

This paper is both a survey and a review of the current state of the debate concerning verisimilitude. As a survey it is intended for the interested outsider who wants both easy access to and some comparison between the respective approaches. As a review it covers the first three books on the topic: those of Oddie. Niiniluoto and Kuipers.

David Miller has demonstrated to the satisfaction of a variety of philosophers that the accuracy of false quantitative theories is language dependent (cf. Miller 1975). This demonstration renders the accuracy-based mode of comparison for such theories obsolete. The purpose of this essay is to supply an alternate basis for theory comparison which in this paper is deemed the knowledge-based mode of quantitative theory comparison. It is argued that the status of a quantitative theory as knowledge depends primarily on the soundness (...) of the measurement procedure which produced the theory; such soundness is invariant, on my view, under Milleresque translations. This point is the basis for the linguistic invariance of knowledgelikeness. When the aim of science is not construed simply in terms of the truthlikeness or accuracy of theories, but in terms of the knowledge such theories embody, Miller's language dependence problem is overcome. One result of this analysis is that the possibility of objective scientific progress is restored, a possibility that Miller's analysis has prima facie defeated. (shrink)

The concept of verisimilitude is an indispensable tool for the fallibilist and realist epistemology. Part of the argument for this thesis consists in the important applications of this notion within the history and philosophy of science. But perhaps the harder part is to convince a sceptical reader of the existence of this concept. A general programme for defining and estimating degrees of truthlikeness for various kinds of scientific statements is outlined in some detail. Ten years after Miller's and Tichy's refutation (...) of Popper's attempted definition, this paper reviews recent developments and debates, and concludes that the treatment the Popperian problem with Carnapian logical tools leads to a new synthesis which turns out to formally contain Levi's theory of epistemic utilities as a special case. (shrink)