We all know the oft-repeated formula from Vitruvius that a work of architecture must satisfy the demands of "Firmness Commodity and Delight" or, as the 20th Century would put it, of "Technology, Function and Aesthetics". There is a further assumption that these three virtues grow together quite naturally like fruit from the same tree. But I would challenge that. In practice it is extremely difficult to reconcile the demands of their different nature: indeed they frequently turn out to be in competition with each other, to dominate the decisions of a particular design or, much worse, of a particular design philo- sophy. Today the fashionable prejudices are either towards a so-called 'autonomous architecture' (art for art's sake) or pure technology (the obsession with a kind of Meccano) each opposed to the other and both opposed to any sense of appropriate habitability. The obligation to meet all three criteria calls for a sort of Hippocratic oath to be exercised in a realm hard to define but which overlaps simultaneously upon areas of aesthetics, morality and politics. And here too it seexhs that it is only the practitioner, rather than the hist- orian or the aesthete, who is aware of the need for this special kind of probity, because he knows damn well the temptations to dodge or suppress whatever doesn't suit his prejudices in the process of design - a process that Alvar Aalto always referred to as a fight for some kind of authenticity. But over and above the need to find a balance between these three conflicting factors, there is a further or fourth demand; and Vitruvius had a word for that too, 'propriety', and that deals with the symbolic aspects of architecture, the extent to which a building can and should represent ideas, call up associa- tions or make reference to historical precedent. Right now this is a most delicate and difficult need to satisfy. The Victorians flogged the notion to death, with the result that the orthodox modernists of the Twenties totally rejected it. For them history was bunk. Fortunately the unorthodox modernists such as Frank Lloyd Wright, Aalto and the late Le Corbusier did not reject these values so that the threads of continuity are there to be followed. Alvar Aalto was, in my View, pre-eminent in the company of the Modern Masters for the sense in which he saw the enemy-to-be not the dead hand of the past but the bad faith of the present, its worship of technology and of formalism and its bondage to bureaucracy. In his buildings, which attended more closely than any other to questions of habitability, we find also many references to historical precedent such as the Pompeian courtyard or the amphitheatre at Delphi. And this is done not at the level of a stylistic game but in the sense that a quotation or reference to precedent will bring an entirely new level of meaning to a work. This is the essence of tradition, of continuity, and without it we float in a cultural vacuum. So much for a point of view: now to the particular case.

My involvement with the British Library building in London began in 1962 when as a young architect I was commissioned with Leslie Martin to prepare a design for the British Museum Library. This, as you may know, is one of the great library collections, if not indeed the greatest, in the world; and the design . in this case was effectively a largeannexeconnected below ground level to the Museum itself. The brief was finite and concise and so was the design: a range of Departmental Reading Rooms for manuscripts, maps, music, oriental material, state papers and so on, were disposed around one huge general reading-room that stepped up and over the L-shaped Catalogue Hall. I was much preoccupied at that time with notions of monumental geometry and of the archetypal form of the "stepped-terrace" - the Reading Room conceived as a sublime hanging- garden brimming with light and held aloft on a massive podium containing the closed book-stacks. That project was approved in 1964 but it was not until sixteen years later that authority to proceed with the construction of a building was given. But by then both site and brief were very different.