My first experience of the work of Sir Basil Spence, as a boy on a family drive to Glasgow on the brave new M8, was a sudden flash of sun reflecting off the shining new crown of St Michael's Church at Linlithgow.

The mediaeval stone crown - an almost uniquely and wonderfully Scottish way of ennobling a high Kirk - had collapsed in the early 19th century. The tower couldn't take its weight and the eventual replacement had to be lightweight, of wood and aluminium. It was both familiar, being an abstract of the stone crown I knew so well at St Giles Cathedral in Edinburgh, and unfamiliar - its clean and sharp brightness at a drab time in our history was hugely enlivening. It represented an understanding of cultural context combined with an optimism for the future that I have seen, since, in all good architecture, and seek in my own.

The crown, completed in 1964, is a collaboration. Credited first to sculptor Geoffrey Clarke, with Spence "advising", the work is so unlike Clarke's usual style as to suggest there is a considerable amount of Spence in there. Certainly my father, who was the structure's engineer (unknown to me at the time - and indeed until a few years ago) tells me all his dealings were with Spence's office.

Clarke was one of Spence's principal collaborators at Coventry Cathedral, and the flash of optimism I saw at Linlithgow is a spark of that great work.

The commission to rebuild Coventry Cathedral, which had been destroyed by wartime bombing, was won in a 1950 competition. Spence's was the only entry to keep the ruins of the old Cathedral and the point, which is emblematic of his concern to balance context with optimistic modernity. His triumph at Coventry is in the ease and grace with which a single, unified and uplifting work of contemporary art is forged.

It's an ease that worked equally well with simple building as with high architecture. Spence's work on tenements in Edinburgh's Canongate, on fisherman's housing at Dunbar harbour and elsewhere, is wonderful; utterly of its place, time and tradition. Looking at the perfect balance between confidence and modesty you wonder why we have so severely lost the plot, for in all of our contemporary frenzy for the flash, the glitzy and the sensational, we are not remotely close to achieving the solidity, lightness and integrity of the best of Spence's work and that of his many talented contemporaries - work that we continue to denigrate and demolish, just as we are starting to value it.

Of course, one of the principal lessons the 20th century has to teach us is the proper limit of such confidence - and where confidence tips over into towering hubris. I went to see Spence's famous - or notorious - Hutchesontown Gorbals towers, demolished in turn, like the slums they replaced, in 1993. I could see their masterful composition, soaring ambition and rugged integrity; but all that was as nothing compared to the despair I felt at the broken society they had fostered.

That Spence, like his many talented Scottish and international contemporaries, so clearly let the general hubris sweep him way over the line adds to - not detracts from - his, and their, importance to the understanding of that balance. Spence's work in the Gorbals sat alongside that of Robert Matthew, founder of RMJM architects and one of the principal architects of London's much-loved, and recently-repaired, Royal Festival Hall.

Spence and Matthew also collaborated at George Square in Edinburgh, demolishing exceptional Georgian buildings and replacing them with exceptional modern ones. The paradox is a complex one, for a wonderful environment was cleared. Matthew, its masterplanner, regretted the loss and was a moving force behind the formation of the Edinburgh New Town Conservation Committee, which led to the recovery of historic central Edinburgh from careless decay - and the ravages of such grand masterplans as he himself had advanced.

However, the demolition at George Square - the hub of Edinburgh University's arts and humanities - created a wonderful environment. Although compromised by the brutally dumb Appleton Tower (without which Matthew's David Hume Tower would look slim and lovely), Matthew and Spence's buildings and their multi-level surroundings are a joy to be in; the essence of flowing, connected modern space. Historic Scotland have recently listed the area, with Matthew's buildings B-listed and Spence's Edinburgh University Library A-listed - the highest category, reserved for a building of international importance.

IT's been suggested that listing replacements, while simultaneously bewailing the demolition that created space for them, is not so much a "paradox" as madness. Not so: there is maturity, and admirable academic detachment, in holding such apparently paradoxical positions to be both true. This doesn't mean - as some suggest - that it's alright to demolish listed buildings and replace them with even better modern ones that will be listed in turn. The measured response to this is that the world is full of unlistable and unloveable buildings and we should practise our redevelopment skills on them, rather than their very fine neighbours.

Buildings are listed for their historic and academic content. But I am no historian and, instead, I love these buildings for how good, and solid, connected and inspirational they are. But I am thankful that the academic perspective mirrors my ordinary one; for our anger at how the 20th century's hubris has lacerated our built environment has blinded us to how good some 20th-century architecture actually is.

I hope this renewed interest in Spence leads to a better understanding of the line he trod between modernity and context. And I wish for his generation's understanding of that balance - and its concentration on simplicity, light and integrity - to reassert itself over our shallow, contemporary architectural culture.

Malcolm Fraser is founder and director of Malcolm Fraser Architects Back To The Future: Sir Basil Spence 1907-1976 is at the Dean Gallery, Edinburgh until February 10, 2008