For the sake of completeness, Macdonald was quoting Prince Puckler, the 19th century landscape gardener. At the beginning of the same chapter he quoted Humphry Repton, who wrote something along the same lines . . .
If it should appear that, instead of displaying new doctrines, or furnishing novel ideas, it serves rather, by a new method, to elucidate old established principles, and to confirm long received opinions, I can only plead in my excuse, that true taste, in every art, consists more in adapting tried expedients to peculiar circumstances, than in that inordinate thirst after novelty, the characteristic of uncultivated minds, which, from the facility of inventing wild theories, without experience, are apt to suppose, that taste is displayed by novelty, genius by innovation, and that every change must necessarily tend to improvement.