The Roman Catholic Church, for all its extent and density, is extraordinarily sensitive to papal leadership. We talk easily of dominance by papal staffs (more menacing in Latin as the Curia ); but the styles of Pius XII, John XXXIII and Paul VI have all shaped the church. Even John Paul I, the "September Pope" as the Romans called him, rid us blessedly of coronations and enthronements. There is little reason to expect that the vigorous and pastoral John Paul II, in what promises to be a long sit on Peter's chair, will have any less impact on the church he loves and heads.

Any effort to spell out Pope John II's agenda, either for the long run of his papacy or his immediate visit to the United States, must take into account his background. Polish Catholicism marks almost everything he says and does. Its proud nationalism, its discipline in the face of a deadly and powerful adversary, its long and intense suffering and its devotion to the Blessed Virgin -- all are clear in the deeds and words of the new pope. He has survived the two tyrannical systems of the 20th century, communism and Nazism, so unlike each other in ideology and so very like in practice.

He is also a scholar and a poet. His philosophical studies took him deep into Husserl's world of phenomenology. If this gave him a reverence for facts, and a distrust of any effort to fit them into straitjackets of preconceptions, it will have direct import for his conduct of the papacy. Finally, as bishop and cardinal he is both architect and sharer in the post-conciliar church.

His personal gifts have had their fair share of coverage. Vigor is part of his charm, and an enormous reassurance to the church. Here is no effete figure, but a strong man whose body is very much part of both his thinking and his loving. He has an extraordinary feel for people in crowds. It is too early to tell the constraints his struggles against tyranny have locked into his soul. He has, however, in his talks in Mexico, clearly indicated one freedom tyranny gave him -- a distrust of systems, and a refusal to allow the church to be tied into any political or economic orthodoxy. He seems to have a touch for the young, is not afraid of them, cares for them and can talk to them. Of all his gifts, this may in time prove the richest.

John Paul II will read the Universal Church strong in the experience of Eastern and not Western Europe. Our easy assumptions of freedom he has seldom been able to share. The want lists of highly developed societies are not familiar to him. His eastward look will show him a church in captivity. His demographic judgment will be as sound as his theology, and he will read right the numbers that pluck the hearts from lesser men. He has already heard the voice of 300 million Latin American Catholics who will, by the turn of the century, be 600 million.

His agenda will thus hardly be that advanced by Time magazine with such perspicacity and zeal for the reform of the Roman Catholic Church. No one can deny serious church concern for the five media topics (abortion, divorce, birth control, the ordination of women and the marriage of priests). This pope must ask wehther or not the church is free to exist, or whether its people are murdered in the streets for believing in it, or whether its bishops are in or out of jail, or whether millions of its faithful are starving. He is likely to find that expanding the agenda of the developed nations to the Universal Church would trivialize the pain and the anguish that must be his daily fare as he looks out on the world the church labors to save.

In the documents he has written one can sense the shape of his philosophical training. His focus is on man, on human worth, on human dignity, on man's rights to work, to education, to culture and to freedom. The word "dignity" must occur 30 times in the speeches and homilies he gave in Mexico. But John Paul II will never settle for the humanist agenda. He will work across to the second step -- that is, man reborn in Christ. The church must bring wholeness even to the most beautiful reaches of the humanist vision of human society. The pope is a pastor, not a philosopher.

Mexico gave us the first serious soundings in his speech to the Third General Assembly of Latin American Bishops in Puebla. Most of it was written at home, and it is balanced, central and kind. It marches easily in the footsteps of Paul VI at Medellin 10 years before, far more than it was given credit for doing in the world's press. Again and again human dignity as "a gospel value that cannot be despised without great offending the Creator" is proclaimed. He talks of his own and Christ's identity with the "disinherited, the sick, the imprisoned, the hungry, the lonely," and speaks with horror of "the growing wealth of the few running parallel to the growing poverty of the masses." He then goes on to say that "we shall reach man, we shall reach justice, through evangelization."

The next day at Oaxaca, and two days later at Monterrey, he gave brief talks to workers in which a different spirit, almost a different man, emerges. In the seven days of his travels, the facts of life of the church in Latin America had had a chance to hit him head on. His focus is still on man, and as always on man reborn in Christ: "The dignity of the human person must prevail above all other things, which in turn must be subservient to man." The church is "not afraid to vigorously denounce all attacks against human dignity." If humankind wants to get hold of a revolution which is getting out of hand . . . if it wants to insure true development of individuals and peoples, then it must revise in a radical form the concept of progress which under various names has left spiritual values behind it."

But the tone is different. We can feel him reach toward his hearers: "The worker, who by the sweat of his brow waters his affliction, must hope that his dignity . . . be recognized fully. He has the right not to be deprived, through manipulations that at times amount to real thefts, of the little that he has; he has the right for his hopes to govern his growth and not be thwarted; the right to that fulfillment which his human dignity and his sonship of God claim."

And finally almost with menace: "For those of you who are responsible for the welfare of nations, powerful classes which at time keep the land unproductive and hide the bread which so many families lack, human conscience, the conscience of the nations, the cry of the deprived and above all the voice of God, the voice of the church repeats with me, 'It is not just, it is not human, it is not Christian.'"

The words in their sincerity fall like hammer blows, and the love behind them is clear. We do not know yet how much this pope will learn and how quickly he will learn it. He has already told us one thing that he, as the Vicar of Christ, wants -- that the church address everything in its own house which "is not just, is not human, is not Christian."

One last word: anyone who thinks he comprehends the breadth and depth and length and height of this man's love -- had best think again.