(... ) I referred to this approach to physical problems by Einstein because I believe that a serious cause of the crisis of modern physics - a universally acknowledged need for new ideas - lies in the tendency towards an unlimited mathematization that becomes almost an end in itself.

In today's flood of physical theories, one finds an impressive confusion between physical reality and its mathematical representations, which - while possibly possessing predictive power - lack physical content or verge on paradox.

Behind this crisis, I think, lies a fundamental epistemological problem, the relationship between mathematics and physical reality. The acknowledgment of this crisis makes every reference to Einstein's work particularly relevant, as it outlines in our century the physical realism in its confrontation with idealism or positivism.

[Excerpt from the text of the preface]