The concern of the Spanish businessmen towards membership in the European Communities took place under defined parameters for the defense of their interests and a purely economic view of the integration project, in the same way as among the majority of Greeks and Portuguese counterparts. Europe was a promise and a guarantee of development, the opportunity to complete the process of liberalization of the Spanish economy, to undertake industrial restructuring and to modernize and professionalize the management of their businesses. Otherwise, Europe was a challenge: they could only survive the best and most effective. This two faces were inseparable, as the two faces of Janus, and can help to explain the changing perceptions about integration and transition from a naive optimism to a widespread skepticism. It coincides with the expansive phase of the Spanish economy, but after that, the growth model began to experiment signs of crisis, in the second half of the sixties.