The Buildings of England, published 50 years ago, was a triumph. Rather than telling us what to see, Pevsner freed us to see for ourselves
Pevsner is 50 this month. Sir Nikolaus may have been dead for 18 years but his name and the monumental achievement it signifies are very much alive. This is a golden jubilee worthy of national celebration, indeed of international celebration, for there is nothing in the world so systematically thorough as The Buildings of England, which might be described as "an inventory of the 100,000 most important buildings in this country". It might be, but that would be akin to calling the Oxford English Dictionary "a list of words".

Pevsner changed this country's attitude to architecture more than any man since Ruskin, whose inspired earnestness he shared. We owe him (and his collaborators) an immeasurable debt: he opened our eyes, he still opens our eyes. But he doesn't make us see. There is a difference. He was not, and never pretended to be, an evocative writer. He describes, and leaves us to do the on-site ocular work. His approach was that of a scientific taxonomist. He was not merely an architectural modernist but a literary modernist. From Joyce through Faulkner to Nabokov (a lepidopterist) and Robbe-Grillet (an agronomist), modernist description was preoccupied with occlusion, with an accretion of detail that inhibits our summoning the object in our inner cinema. This is a device that aspires to neutrality, a neutrality that Pevsner seldom ruptures - but when he does … His one-liners and taut dismissals and laudatory clauses are all the more potent for their infrequency.

The discipline with which he rationed himself is admirable. And of course it goes against the "amateur spirit", the heart-on-sleeve expression of enthusiasm. There can be no doubt that he was an enthusiast for the buildings of his adopted country (which he loved more than it loved him) – why would he have put himself through such a gruelling assault course had he been otherwise? He was also an amateur in the now archaic meaning of that word.

What he wasn't was an amateur in the sense of dilettante. Builders, masons, surveyors, architects, engineers, carvers, ironworkers – the overwhelming majority of those who have professed these callings down the centuries that Pevsner devoured have indeed been professionals. Yet the study of their work was largely undertaken by passionate dilettantes who sought to pass off torpid imprecision as "impressionism".

He was a progressive who didn’t like progress when he saw what it produced

If we consult a work of, say, mycological or avian reference, we expect exactitude rather than bumbling guff wrought with a pen dipped in lard. So why should buildings be different from fungi and birds? The easy reply is that buildings are humankind's rather than "natural" creations. But it is, equally, wrongheaded: if humankind can create the Zwinger and Blenheim and the Stupinigi, it should be acknowledged capable of creating an exact way of classifying them.

I use those examples of the baroque because the one apercu I've enjoyed this past week is to do with Pevsner's taste, and his initial specialism was the baroque. It is necessary to amend Borges' famous dictum that "every writer creates his own precursors", which is a neat way of saying that because E was influenced by A, B, C and D we necessarily come to see A, B, C and D in a fresh configuration and discern a connection between them, even if that connection is only E.

Maybe the same goes for those buildings and architects Pevsner admired. His fondness for Victorian revivalism is as well documented as his antipathy to 20th-century revivalism; and his antipathy to the expressionistic modernism of the 1960s and early 1970s is consistent with his championing of the international modernism of the 1920s and 1930s.