Constitutions and an Idea of "Conservatism"

This is from a certain Edward Shepherd Creasy, in 1848:

“The ancient Athenians had a national oath by which each generation of citizens bound themselves to defend the state, and to hand it down to their descendants better than they had found it:—
…

“That oath was conceived in the truest spirit of Conservatism; and in its spirit should each Englishman act who truly venerates the Constitution of his country, and wishes to preserve it unimpaired. For that purpose, while religiously guarding its primary institutions from the experiments of the mere theorist and the assaults of the destroyer, he must work out its vital law of growth and development, and endeavour to apply its principles to the emergencies of the present time, as his ancestors did to the emergencies of the times gone by. Finality is a delusion, and Revolutionary Change is madness. The only safe course is the good old track of Constitutional progress by means of Constitutional Reform.”