to that goal, and it is hoped that it will incorporate further works dealing in an exact way with interesting philosophical issues. Zurich, April 1973 Mario Bunge From the Preface to the First Edition It may seem odd that aseries of works devoted to the natural sciences should indude - indeed begin with - a volume on phi- losophy. Today, of course, it is generally agreed that philosophy and natural science are perfectly compatible. But to grant the theory of knowledge such a prominent position implies not only that these two fields are compatible, but that there is a natural connection...