Sir: Professor Patrick Hodgkinson is right to assert (letter, 18 February) that Mendelsohn and Chermayeff's 'Cohen' house ('One good functionalist deserves another'; Architecture, 10 February) raises 'questions of principle about the listing and preservation of architecture we call Modern'.

He is right, also, to say that the inside and outside of the house arose from a single vital conception - as did the houses of other great Modern architects such as Frank Lloyd Wright and Le Corbusier. It is, of course, precisely this principle of integrity and honesty that distinguishes early Modernism in architecture from what preceded it - 19th-century 'styles' and mannerism.

However, Professor Hodgkinson is wrong to imply that Mendelsohn would have agreed that his house needed changing because the occupants had aged or have supported the particular changes proposed by Sir Norman Foster. He might well have hated them just as living Modern architects have hated and indeed successfully resisted proposed changes to their designs.

The problem is that it is not just a question of 'use' or 'functionalism'. Erich Mendelsohn designed buildings of stunning power, beauty and elegance of conception. He was an architectural genius comparable to Picasso or Stravinsky.

The impetus of his work came, as Hodgkinson correctly states, from aesthetic movements such as Futurism whose iconoclasm should not be taken literally - they did not actually set out to blow up museums - but as a preamble to an astonishing revolutionary period of creativity.

We are still very much in the process of absorbing the achievements of the great innovators like Erich Mendelsohn. This is not a matter of nostalgia or sentimentality, words which imply a comfortable, lazy perspective on the past, but rather of respect for the ineffable.

Erich Mendelsohn was a very great master of architecture - Foster is a pupil of Mendelsohn's pupil. The sorcerer's apprentice should leave well alone.

Yours faithfully,

DAVID HAMILTON EDDY

London, E9

18 February