Everybody appeals to Antiquity: whether S Pius V (bull Quod a nobis " ... ad pristinam orandi regulam conformata revocaretur ...") or Archbishop Cranmer ("these many years passed, this godly and decent order of the ancient fathers hath been so altered, broken, and neglected ..."). And Vatican II, quoted by S Paul VI ("restituuntur ad pristinam sanctorum Patrum normam nonnulla quae temporum iniuria deciderunt ...").
Smart chaps sometimes point out the problems here: Dom Gregory Dix loved to explain how little the 'reformers' actually knew about the worship of the 'Primitive Church' because relevant texts had not been published, but earlier (1904) Wickam Legg acknowledged that "Appeal to Antiquity may from imperfect knowledge of antiquity fail here and there". He comforted himself, however, with the thought that Antiquity "is a better principle than that which approves every abuse that has grown up in the Church ...". Legg footnotes the contrary opinion of Henry Manning: "But the appeal to antiquity is both a treason and a heresy. It is a treason because it rejects the Divine voice of the Church at this hour, and a heresy because it denies that voice to be Divine".
But the problem tends to be "Which Antiquity?" In Manning's time, the 'Antiquity' to which men appealed might often be the medieval usages of English Catholicism. Legg quotes a 'remarkable letter written to Cardinal Manning in 1866 by Mgr Talbot, who was in the household of Pius IX' "Your rule ought to be the Bullariun Romanum, and not the opinions of Dr Rock".
But Rock (and Pugin and the Medievalist Anglican Ritualists) are not the only people whose mirage of a normative Antiquity is open to question. In the 1960s, the authentic early Roman liturgical Apostolic Tradition of Pope S Hippolytus was immensely influential. It supplied the Eucharistic Prayer which, in our post-Conciliar Church, is used in the overwhelming number of Eucharistic celebrations. And the Consecratory Prayer by which Latin Rite bishops are consecrated. Magnificent stuff.
But ... oops-a-daisy ... unfortunately, the document concerned is now universally realised to be neither authentically early Roman nor to have anything whatsoever to do with anybody called Hippolytus or, indeed, with any pope. The tectonic plates in Academe can shift a frightfully long way in a generation or two. Doesn't that make life fun?
And dodgy operatives may use the siren call of "Antiquity" in less than honest ways. S Paul VI (Missale Romanum) tried to palm off on us the idea that the Penitential Rite at the beginning of Mass was one of the Patristic features which had sadly slipped out of the Liturgy and ought to be restored. (Even more slippery was his attempt to attribute this opinion to the Conciliar Fathers of Vatican II: whatever you my think of the decree Sacrosanctum concilium, it did not make this claim.)
I am immensely grateful to the Archibibliopola of Oxford, the erudite Mr Christopher Zealley, MA., for sending me Legg's monograph on Cardinal Tommasi, from which I have plagiarised much of the first part of the above. Learned strangers visiting Oxford may need to be told that "St Philip's Books Ltd." is down St Aldates, more or less opposite the entrance to the Meadow. It is full of Catholic things and all fine literature, and has a rather good plaster ?Stuart ceiling.