This Festschrift volume in honour of Prof. E R Caianiello contains invited papers of eminent scientists who have worked in the several areas to which Prof. Caianiello has given seminal contributions: quantum field theory, foundations of quantum mechanics and maximal acceleration (Vol. 1); neural nets, general systems theory and various topics of cybernetics (Vol. 2). The wide range of topics covered shows the fruitfulness of a higher unifying perspective on seemingly diverse subjects.