There is ample evidence as to how the modern masters, in their shared pursuit of formal inventions and constructional inventions, variously referred to past examples they had freely chosen as guides that could inspire and support them in their strenuous pursuit of new things. The buildings shaped like soft clouds and gelatinous bowels, or the spiked bravura pieces designed by today's fashionable architects have no relation with either construction or history. Louis Kahn, instead, kept form, structure and history paradigmatically together. The book systematically reviews the intense structural experimentation that, in terms not just of building engineering but of spatial and representational potential, marked Kahn's work since the beginning and would eventually lead him, after a long apprenticeship, to an almost constant adoption of 'hollow' structural forms. By reviewing this long and intense journey of research, the book underlines how Louis Kahn, in each work and based on a constant dialogue between structural innovation, building tradition and figural evocation, succeeded in awakening our interest in a new 'fascinating' structure and at the same time our emotion for a deeply meaningful, universal and timeless form.