The Idea of Inevitable Progress versus Archaism

Philosophers and theologians alike should heed a distinction I found in Henri de Lubac's magisterial The Mystery of the Supernatural (Herder and Herder, 2001, originally published in French in 1965, p. 18):

Lastly, returning to the essence of an older position can never be purely and simply a return. Archaism . . . of this kind is always deceptive. It is as illusory, in the reverse sense, as the idea of inevitable progress.  "Those who wrote before us are not our masters, but our leaders" [non domini nostri sed duces fuerunt]. (Guibert de Tournai, "De modo addiscendi," Revue neo-scholastique, 1922 : 226)