Below are listed the principle printed sources used in the researching and writing of this book.

Betti, Emilio - Teoria Generale della Interpretazione 2 vols. 1955
Black, Max - Critical Thinking (Prentice-Hall, New York) 1946
Brentano, Franz - Psychology from an Empirical Standpoint, 1874.
Farber, Marvin. - The Foundation of Phenomenology: Edmund Husserl and the Quest for a Rigorous Science of Philosophy, 1943
Feigl, Herbert - Logical Empiricism & Logical Empiricism and the Special Sciences : Reichenbach, Feigl, and Nagel
Galileo, Galilei - Dialogue Concerning Two New Sciences. Trans. by Henry Crew and Alfonso de Salvio. New York, 1954
Heidegger, Martin -  Being and Time  trans. from Sein und Zeit, 1928
Hempel, C. G. - Aspects of Scientific Explanation and Other Essays, 1965
Husserl, Edmund  - Method and Phenomenological Philosophy, trans. by Hebert Speigelberg.  Journal of the British Society for     Phenomenology. 1 1970
Jones W.T. - A History of Western Philosophy (4 volumes), Chicago 1975
Gadamer, Hans-Georg - Truth and Method. 1975
Habermas, Jürgen - Knowledge and Interest (Inquiry, Oslo 1966 No. 4)
Merleau-Ponty, Maurice - Phenomenology of Perception  trans. U.K. 1962
Merton, Robert K. - Social Theory and Social Structure 1957
Mill, John Stuart  - A System of Logic,  London. 1904
Næss, Arne. D. - Communication and Argument - Oslo 1971
Næss, Arne. D. - Interpretation and Preciseness - Oslo 1953
Ogden, Charles K. - The Meaning of Meaning - Cambridge 1923
Quine, V.W. - From a Logical Point of View. Harvard 1980
Ricoeur, Paul -  Explanation and Understanding in From Text to Action, trans. Kathleen Blamey and John Thompson  (Northwestern University Press) 1991
Ryle, Gilbert - Philosophical Arguments, Clarendon Press, 1945.
Sartre, Jean-Paul - The Problem of  Method, trans. Hazel E. Barnes,  London 1963
     - Critique de la Raison Dialectique (translated as Critique of Dialectical Reason), 1960
     - Being and Nothingness translated from L'Être et le Néant.1943
     - The Problem of Method translated from Question de méthode (from Les Temps Moderne)
Spiegelberg, Herbert  The Phenomenological Movement (2 vols), The Hague 1965
Stebbing, L. Susan - A Modern Introduction to Logic, London 1950
Wittgenstein, Ludwig - Philosophical Investigations - Oxford 1958
Wimsatt and Beardsley - The Intentional Fallacy 1946