Preface (Korean)
(2016)
Introducció
(2009)
Introducción
(2007)
Introducción
(2003)
Foreword (Typescript, 2 pp.)
(1978)
Prefazione (2 pp.)
(1978)
Editorial
(1971)
Introduction in Adam Schaff >Marxism and the Human Individual< (Typescript for publication, 8 pp.)
(1970)
Preface to Philosophy and Revolution, New York (Columbia University Press), 1989, pp xxi-xxii.
(1981)
Foreword
(1978)
Religion and Society
(1978)
Introduction
(1975)
Foreword
(1974)
A Nuestros Lectores
(1973)
Introduction
(1970)
Introduction
(1970)
Introduction
(1970)
Editorial
(1968)
Introduction
(1968)
Prefacio
(1967)
Foreword
(1967)
Preface
(1966)
Foreword II
(1965)
Preface
(1965)
Introduction
(1965)
Introduction
(1965)
Introduction
(1965)
Foreword
(1964)
Foreword
(1964)
Preface
(1962)
et al.: Introduction
(1961)
Afterword
(1961)
Foreword
(1960)
Foreword
(1959)
Introduction
(1948)