This book argues that apart from a number of ambiguities and inner tensions, Marx' and Engels' historical materialism suffers from a misconception of the nature and motive power of historical development and transformations on which their unwarranted confidence in the inevitability of the transition from capitalism to socialism and eventually classless communist society is based; and from a consequent failure to address the problems of accomplishing this transition - the desirability of which is not denied. No finished alternative is offered, but some elements of a better version retaining the critical and revolutionary edge of Marx' and Engels' own are suggested. Others doubtlessly remain to be thought out.