Born in 1928 outside of Chicago, Illinois, Karel Lambert graduated from High School in Dowagiac, Michigan, and entered the Navy Air Force. After military service, he received a BA (1950) from Willamette University in Salem, Oregon, and an MS a year later from the University of Oregon (Experimental Psychology). He finished graduate school at Michigan State University where he was elected to the national honorary society: Phi Kappa Phi. After completing his Ph.D. Thesis (A Logical-Mathematical Analysis of Tolman's Theory of Learning ) in 1956 under Henry S. Leonard (Philosophy) and M. Ray Denny (Psychology), he accepted a position as Assistant Professor in the Psychology Department at the University of Alberta in Canada. There he began an experimental laboratory, published animal studies in learning and motivation (the most significant of which was the discovery of a species of latent learning called latent inference learning), and taught both graduate and undergraduate courses in psychology, and especially in physiological psychology.

While writing his Ph.D. Thesis, he came to believe that a revision in standard predicate logic, one accommodating singular terms like 'the bat hovering over the man suffering from alcoholic delirium', was needed for an adequate formalization of most psychological theories of learning. So, in addition to experimental work at the University of Alberta, he pursued, independently of other pioneers (notably Henry Leonard, Hugues Leblanc, and Jaakko Hintikka), the development of a version of non-classical predicate logic he coined "free logic". He published several technical papers on the subject culminating in the first consistent and complete free theory of definite descriptions in 1962 and 1963 . In these studies he discovered the basic property of any free theory of definite descriptions. It is now known as "Lambert's Law". Because of the continuing shift in his primary research interests to logic and the foundations of science, he accepted a position in the early 1960s as Associate Professor of Philosophy at the University of Alberta. In 1963, he accepted an appointment as Full Professor and Chairman of the Dept. of Philosophy at West Virginia University in Morgantown, West Virginia.

Along with administrative responsibilities, he continued to explore (and publish) various treatments of free logic and free definite description theory. These included a study co-authored with Robert K. Meyer ('Universally Free Logic and Standard Quantification Theory') in the Journal of Symbolic Logic (1968) and a study co-authored with Bas van Fraassen ('On Free Description Theory'') in the Zeitschrift fuer mathematische Logik und Grundlagen der Mathematik (1968). While still at WVU, he received a distinguished teaching award and spoke at an international conference on free logic at Michigan State University. He also developed a set of lectures on the philosophy of science. (These lectures ultimately emerged as a book in 1970, co-authored with Gordon Brittan Jr. entitled An introduction to the Philosophy of Science. Now in its fourth edition it has been translated into German, Italian, Spanish, and Japanese, among other languages.)

In 1967 he accepted a position as Full Professor at the University of California, Irvine (UCI). In 1969, he was awarded a research grant from the UCI Humanities Institute to underwrite his own contribution to, and editorship of, a book entitled Philosophical Problems in Logic (Reidel,1970); it includes essays from an international conference on free and modal logic organized by him at UCI in 1969. In 1970 he was Visiting Distinguished Professor at the University of Oslo giving a set of lectures on the famous Meinong-Russell controversy over nonexistent objects. During the same year, he was an invited speaker at the international commemorative conference on Meinong at the Karl Franzens Universitaet in Graz, Austria, and was appointed as a Research Fellow at the Internationales Forschungszentrum fuer Grundfragen der Wissenschaften in Salzburg, Austria investigating the relationship between scientific explanation and scientific understanding. (Later, in 1975, he was appointed to the Advisory Board of the Forschungszentrum.)

From January 1, 1973 until July 1, 1973, he was a National Endowment for the Humanities Senior Fellow. He spent this period in Europe working on problems in philosophical logic. (Most of this research appeared subsequently in journals in the latter half of the 1970s.) During this period he was also invited to give a series of lectures at the Karl Franzens Universitaet in Graz, Austria on the concept of existence in modern logic. In 1974 and 1976, he received Fulbright-Hays Awards to pursue research in various universities in Austria and Germany, and to attend international conferences where he presented the results of research mainly concerned with the ontological foundations of logic and mathematics, and, to a significant degree, with Meinong's views on these matters. At about this time Professor Paul Weingartner of the University of Salzburg and he initiated a Scholarly Exchange Program at both the graduate student and faculty levels between the Departments of Philosophy at the Universitaet Salzburg and UCI. It has flourished since 1975, and, indeed, has been expanded to include the UCI Dept of Logic and Philosophy of science in the school of Social Science. The program is unique at UCI.

In 1978 The Volkswagen Foundation asked him to serve as a member on an international committee charged with developing a four year International Conference on Science and Ethics. It was held in Dubrovnik, Jugoslavia from 1979-1983. He also served as a participant in these conferences speaking on the relationship between scientific explanation and scientific understanding. In 1979, he was awarded a National Endowment for the Humanities (NEH) Summer Stipend. It helped to underwrite the research in a set of lectures he was invited to give on the foundations of free logic at the College de France in Paris in the spring of 1980. (These lectures were subsequently published in the journal Inquiry (1981) under the title, ‘The philosophical foundations of free logic’). He also received the Medal of the College de France in the same year. From January 1, 1980 until July 1, 1980 he was a Fulbright-Hays Senior Fellow spending most of his time in Salzburg doing research on Meinong's theory of objects and also lecturing both on predication and on scientific explanation.

In 1981 Professor Hide Ishiguro asked him to contribute a book on Meinong's theory of objects and its implications for modern philosophical logic for her series on the relationship between analytic and continental philosophy published under the auspices of the University Press at Cambridge. Based on his 1980 Fulbright lectures in Salzburg, it was published in 1983 under the title Meinong and the Principle of Independence. In 1984 he was made Honorary Professor at the Universitaet Salzburg, and, also, was Distinguished Visiting Professor in the Dept. of Theoretical Chemistry at the Universitaet Ulm. (The invitation from Ulm was occasioned by his 1969 paper 'Logical truth and microphysics', in which van Fraassen's novel model theoretic technique of supervaluations was applied for the first time to explain microphysical reasoning based on the Copenhagen interpretation of quantum mechanics, and by lectures given by him at various other German universities on the relation between scientific explanation and scientific understanding; the essence of these lectures has been summarized in his recent essay ('Prolegomenon to a theory of scientific understanding' in Gerhard Schurz's 1988 anthology Erklaeren und Verstehen in der Wissenschaft).In 1986, he was nominated for the Humboldt Prize in Science, appointed Adjunct Professor at Montana State University, and was promoted to the category of Above Scale Professors at UCI . In the same year, he received an NEH Summer Stipend to underwrite research on the theory of definite descriptions, an important part of which appeared in an article ('A theory about logical theories of expressions of the form 'the so an so', where 'the' is in the singular') at the invitation of the editor of Erkenntnis for a commemorative issue dedicated to Rudolf Carnap and Hans Reichenbach (1991).

In 1989, Oxford University Press asked him to compile a set of essays on applications of free logic (Philosophical Applications of Free Logic) and to write an introduction. It appeared in 1991. In the same year he was awarded a University of California Humanities Institute Grant to underwrite an international conference on predication in science and philosophy. The essays from this conference were subsequently published, under his guest editorship, in the journal Topoi. In 1991 he was the recipient of a Festschrift (Existence and Explanation) edited by W. Spohn, B. van Fraassen and B. Skyrms. In the same year he was invited to give the inaugural Bielefelder Philosophische Vorlesungen (1992), and in December of 1992 was the honoree at an International Conference on Free Logic in Salzburg. (The inaugural lectures are the content of a book entitled, Free Logics: Their Character, Genesis and Some Applications Thereof published by Akademische Verlag, Sankt Augustin bei Bonn (1997)). The essays from the conference are among those to appearing in a collection entitled, New Essays in Free Logic: In Honour of Karel Lambert, edited by Edgar Morscher and Alexander Hieke of the University of Salzburg. It was published by Kluwer in 2002

In 1994 he became Research Professor of Logic and the Philosophy of Science at UCI. (In 1994 a monograph length essay ('Outline of a theory of Scientific understanding'), co-authored with Gerhard Schurz appeared in Synthese , and in 1997 a paper co authored with Raymond Gumb, a computer scientist, entitled 'Definitions in nonstrict positive free logic' appeared in Modern Logic.) In 2000 he was invited give a Plenary Address to a joint session of the American Mathematical Society and the Association for Symbolic Logic; it was entitled 'Set theory and Definite Descriptions'. He is the author of a lengthy survey article entitled 'Free logics' in a Guide to Modern Philosophical Logic edited by L. Goble and published by Blackwell's in 2001. Cambridge University Press published is book Free Logic: Selected Essays in 2003. The work in this volume, consisting both of new essays on free definite description theory and essays which are amplifications of work on free logic, its foundations and applications composed over the past forty years, was supported in part by a University of California Presidential Fellowship in the Humanities (1993). In April of 2003, Brian Skyrms and the Dept of Logic and Philosophy of Science sponsored an international conference in philosophical logic in his honor.

Finally, he has contributed over a hundred articles in psychology, philosophy, computer science and AI journals, has edited, authored or co-authored twelve books, written pieces for various encyclopedias on the topics of free logic, definite descriptions, Meinong, etc., served (and continues to serve) on the editorial boards of many prominent journals, has refereed many articles and proposals for philosophy and mathematics journals, publishing houses, and various private and federal granting agencies (e.g., The Guggenheim Foundation, The Fulbright-Hays Program, NEH, National Science Foundation, etc.). Often asked to evaluate both the professional performance of colleagues who are candidates for chairs internationally and academic programs in universities both here and abroad, he served on the nominating committee for the 1966 Kyoto Prize in the arts and moral sciences that was awarded to W. V Quine. He belongs to many professional associations, and has served as an officer in them periodically. He has taught each winter in the Department of Logic and Philosophy of Science in the School of Social Science at UCI. He still gives invited addresses at international conferences, in the US and abroad, and is available for consulting work on educational programs, both locally and nationally.

Karel Lambert has been married for over a half century to Carol Carruthers, and has three grown children, Karel (a microbiologist and patent agent), Kathryn (a market manager for an international corporation), and Christopher (a college instructor in England, sometime poet and antique dealer).