AS AN INSTITUTION the papacy bridges almost 2,000 years of contentious if not violent historical development. Its supreme pastors have served as both the architects of western civilization and at times the intransigent enemies of progress.

Although modern scholarship has challenged the authenticity of the Gospel pericope, "You are a Rock and upon this Rock I will build my church" (Matthew, 16:16-18) in which Christ invested Peter with the papal office, incontrovertible evidence points to Peter as spokesman of the apostles and leader of the primitive church. By the late second century Pope Victor I, Peter's 13th successor as bishop of Rome, claimed a "care for all the churches" that is described by Ireneus of Lyons as potentior principalitas -- a more eminent presidency, at least. With Leo I (440-461), the bishop of Rome asserted a world wide primary although the phrase Roma locuta, causa finita -- "Rome has spoken, the case is closed" -- has been honored more in the breach than in the observance.

It is on the basis of this type of historical background that Bernard Hasler's How the Pope Became Infallible must be evaluated. And it is this element that is missing as the author engages in what can only be termed a long, repetitious, diatribe against Pope Pius IX (Pio Nono), the pope who called the first Vatican Council in 1870 at which the doctrine of papal infallibility was defined. Basically the doctrine says that the pope, by virtue of his position, cannot make a mistake when he is officially defining matters of faith or morals as contained in the sacred scriptures. Hasler, himself a priest until his death last year and a man with five years of experience in the Vatican Secretariat for Christian Unity, accuses Pius IX of almost singlehandedly forcing the definition of papal infallibility and supremacy on the Catholic Church.

Depicting Pio Nono as vain and ambitious, Hasler fails to take into account the pope's reputation for affability and wit among diplomats and his great worldwide popularity among the mass of the faithful. Instead, he credits him with a Machiavellian astuteness, and describes him as engineering a byzantine maneuver to adopt the infallibility doctrine and humiliate the opposition.

Hasler makes little attempt to explain the secular atmosphere in which the proponents of the definition of papal infallibility were working. In particular he gives no insight into the mentality of one of the chief engineers of the definition's passage, the English archibishop (later cardinal) Henry Edward Manning. An archdeacon of the Anglican church before converting to Catholicism, Manning was so affected by the extravagant claims of 19th-century scientists and Positivists -- from T. H. Huxley to A. Comte -- that they had grasped absolute truth in the physical order, that he felt the church had to prove its possession of indisputable truth in the spiritual order.

Nor does the author give a clear analysis of the opposition to the definition within the Church by men such as John Henry Newman, another convert from Anglicanism, also later a cardinal, who felt the definition was both "inopportune" and needless. In the end some 140 cardinals and bishops, including several Americans, of the 600 or so prelates present, left the council -- in protest, although with the pope's permission -- before the solemn declaration. All submitted later.

Ultimately Hasler challenges papal infallibility on the basis that the council was not a truly representative ecumenical gathering with the freedom necessary to make such a decision. For his troubles, particularly for his attack on the character of Pio Nono, the author earned the enmity of the Roman curia who suggested to Pope John Paul II that he be stripped of his priesthood. The pope passed on the suggestion to Hasler's bishop in St. Gall, Switzerland. But the bishop refused because Hasler was a good priest and was by then dying of cancer.

It is unfortunate that Hans Kung, in a long and sometimes vitriolic introduction, has used this jejune volume for his attack on the doctrine of infallibility. It was this statement that proved the final straw for the German bishops who censored the Tuebingen theologian and had the Holy Father revoke Kung's title as a "Catholic theologian."

All in all the book is a feeble statement of the case against infallibility, whose usefulness, if not authenticity, has often been questioned by competent theologians. The book is a poor monument to a man who was a sincere but limited historian and a good priest.