Eduardo Torroja

"[E]very structure has a resistant function to fulfill... to ensure ...the static equilibrium of the structure for a long period of time."

"Mathematics is merely a convenient tool by which the designer determines the physical proportions and details of a planned structure in order to transform his ideas... to the actuality of a finished structure."

"Long before... our techniques of today, men could conceive and build structures adapted to the requirements of resistance... because he had observed... the branches of a tree bending under the weight of fruits and the tensioned cords of strings in which children have rocked from time immemorial..."

"[El Instituto Técnico de la Construcción y del Cemento] had shown that it is possible in Spain to create organizations in which there exists a perfect harmony between different professions, between those above and those below; organizations in which everyone is able to live a life of high human rank, as gentlemen, a life of mutual respect and help and of maximum personal dignity."

"Structural design is... very much concerned with art, common sense, sentiment, aptitude, and enjoyment of the task of creating opportune outlines to which scientific calculations will add finishing touches, substantiating that the structure is sound and strong..."

"The technical literature on structural engineering abounds with theoretical works of a mathematical nature, but few publications are concerned with the various kinds of structures or the fundamental reasons for their existence."

"Construction methods are... variable for each specific material."

"The material in all elementary parts of a structure must have the properties of resistence to all internal forces produced by general loading conditions and by the action of any exterior force."

"[M]aterials should resist mechanical forces and other effects... starting with all types of loading and external forces... and with the mechanical properties of the materials... constitutes the part given most emphasis in technical books and schools."

"The equilibrium... in order to become static—should be steady, permanent, lasting. ...This type of equilibrium... is... independent of any scale. A reduced model will show the same effects as the proper structure. Experiments on models are simple and... instrumental for understanding such structural problems."

"[T]here are three different but interconnected conceptions to be considered in every structure, and in every structural element involved: equilibrium, resistance, and stability."

"Before a man can successfully plan a structure... he must study, from every possible angle, the ultimate purpose of his building. Attention must be directed to the basic structural concept before the mathematical process of calculation is undertaken."