Structural design is... very much concerned with art, common sense, sentiment, aptitude, and enjoyment of the task of creating opportune outlines to … - Eduardo Torroja

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...

One should become so familiar with the structure as to have the feeling of being, in full vitality and sentiment, part of it and of all its elements. ...it is necessary to achieve a sincere Einfühlung [empathy] of the process of resistence... through the deformation that is always essentially united with the process of stressing. ...[T]he comprehension of a structure requires intuitive knowledge of the ethology of its resistance and of its constituent materials.

Stone can effectively resist compression but is relatively weak in tension. Because of its mass and weight it may be used advantageously in structural types that can be made stable by the proper weight (dead load, gravity) and are but slightly exposed to lateral forces.