In landscape architecture, incorporating modern design elements into old settings gives rise to philosophical questions on conservation. This author examines the fittingness of a creative conservation concept issued from John Dewey's theory of art as a continuum, the theory of the unity of time and space. Transposing it to landscape design, he shows by two examples how he took the features of history like threads to weave them into a virtually new composition, whose purpose was to harmonize materials that in themselves might once have been in opposition. He shows what he calls two different interpretations of two historic landscapes, the first (Ditchley Park, north of Oxford) made over 40 years ago, and the second (Hartwell House near Aylesbury) currently. -- AATA