Italy’s contribution to post-war architecture has been equivocal, and the critical assessment of many of her new buildings an uneasy exercise. One among the many difficulties has been the brilliant and formally perverse way in which Italian architects have underlined the falsity of the old equation between classical purity and machine technology that has bedevilled critics and architects alike since long before Le Corbusier made it eloquent in Versl une Architecture. Using traditional craft and pre-technological materials to produce supposedly mechanistic effects of smooth precision, the Italians coincided with Le Corbusier's beton brut, in accidentally undermining the symbolic values of the machine aesthetic, and reduced its stern canons toa formalistic game. Through all the resulting chaos and equivocations. Gio Ponti (everybody’s favourite ides of an Italian artist-architect) has picked his way with a politician's skill, dashing off one sizzling design after another, many of them elegant trivialities, infuriating his more committed contemporaries. Then in 1958 he emerged as co-captain with Pierluigi Nervi of the team that conceived a building that proves him to be more than just an elegant trimmer to the winds of fashion.

 
The Pirelli tower, flanking the Piazza outside Milan's abominably rhetorical central station, remains one of the half-dozen towers of the fifties that matter. It re-stated all the Italian formalist equivocations aver the machine aesthetic and yet gave that idiom new life as surely as the Seagram building. By one of those coincidences that make history improbable (though not as improbable as those surrounding the inception of the Seagrram building) the impeccable structural logic of that phase of Nervi’s career came into conjunction with certain formal preoccupations of Ponti’s, and the world now has a building that is not formalist in spite of the care given to the study of its form, a tough-minded business building that is not just a rentbox, an advertising symbol that is not just a gimmick - and all this realised in a building that is manifestly a unified, integrated conception, in spite of the hours of wont and horse-trading table that must have gone into its design.

 
The result is a building that looks razor-thin from end-on, and almost is; two main facades bend back to meet one another in plan, but never quite make it because an airgap runs up the full height of the building just where the cutting-edge of the razor should be. Up the main facade run a pair of slender tapering columns, outward manifestation of Nervi's all-tapering structure within. At the top they carry a flat lid of a roof, but not visibly; the glass wall of the facade stops, and the columns are bent back inside, one floor below the roof, which float above another airgap. The three air gaps down each end and one under the roof - give the tower the air of being a front, a back and a lid, on the point of joining to make a closed box, not vet closed, but for ever aspiring to do so.

 It is that aspiration that Ponti wants the observer to see, for the Pirelli, like most great modern buildings, is a statement, a proposition (‘slogan’, says Ponti). As a counterblast to the endlessness and repetitiveness of curtain-wall architecture. Ponti wanted Pirelli to be read as closed form: a forma finita. Because it is just on the point of closing it is read as closed far more securely than if it were finally shut and finished. It may not be a very grandiose ambition to create a building in which a fairly simple formal intention is to be read, but it is quite something to have achieved it in an idiom like that of modern architecture, which has produced so many buildings that will be forever inscrutable to the main in the street or piazza.

Banham R. Age of the Masters: A Personal View of Modern Architecture. Harper & Row., 1975. P. 116-117.