On March 4, 1979, Pope John Paul II presented to the Church his first encyclical, Redemptor Hominis, "The Redeemer of Man." Redemptor Hominis was very well-received, and became a constant reference point for Pope John Paul's entire pontificate; he referred consistently to the themes introduced in the encyclical, and many subsequent writings and addresses extended and developed those themes. There is every reason to believe that Pope Benedict XVI's first encyclical, Deus Caritas Est, will be as fundamental to his pontificate as Redemptor Hominis was to Pope John Paul II's. Deus Caritas Est is a splendid reflection on love that exhibits many of the intellectual gifts we came to know through Pope Benedict's work as a theologian. Many things could be said about Deus Caritas Est, but I will restrict myself to three points: its direct confrontation with philosophical alternatives; its comments on charity in part two; and its confrontation with Marxism.

Any reader of papal documents becomes aware of certain formalities and customs unique to the literature, including for instance the use of the royal "we" and cryptic references to alternative views. This latter custom in particular provides those alternatives the wiggle room to claim, "Who is the Pope talking about, anyway?" as proportionalists did after John Paul II's encyclical, Veritatis Splendor.

With great effect, Deus Caritas Est abandons this custom and names and even cites the Holy Father's major opponents. Thus, in the prefatory comments of his discussion about love, Pope Benedict confronts the trenchant allegations made against the Christian view of love; in particular, he cites Friedrich Nietszche, according to whom "Christianity had poisoned eros, … which gradually degenerated into vice." Pope Benedict continues, "Here the German philosopher was expressing a widely-held perception: doesn't the Church, with all her commandments and prohibitions, turn to bitterness the most precious thing in life?" (DCE no. 3) Nietszche's is an enormously powerful and influential critique of Christianity; one that retains its power today: isn't this exactly the allegation placed at the feet of the Church: your rules, your regulations, constrain our free pursuit of pleasure, and furthermore, we suspect these rules arise from your spite? Confronting it head-on as Pope Benedict has reflects, at minimum, confidence that Christianity can prevail even in open confrontation with the strongest and best alternative views. If that confident methodology sounds familiar, it should; it's the methodology embraced by St. Thomas Aquinas. Good enough for Thomas, good enough for the popes, I'd say.

But methodology isn't everything, and confidence can wilt in confrontation. Of greater importance than the decision to dispense with the ritual of cryptic allusion is the substance of the encyclical's claims about love. The culture claims the Catholic Church opposes the body and sexual love; but what is the culture's response? The culture's great "yes" to the body and to sexual love, the Pope notes, is in treating them as commodities (no. 5). In the name of freedom, we literally treat our bodies and sexuality as chattel; objects of sale and trade.

The encyclical's second part develops the notion of charity as an exercise of the Christian community, the Church. Pope Benedict notes yet another charge made against the Church, one that arises initially externally from a Marxist perspective, but later finds voice internal to the Church. This is the allegation that the Church allows charity to run cover for the rich, who soothe their consciences by token gifts to the poor whom they otherwise oppress; that the poor need justice, not charity. Like Nietzsche's allegation, this one possesses enormous power, and it is neither an admission of weakness nor an indication of a preoccupation with 20th century concerns to admit the strength and even brilliance of Marx's analysis. It's comically ironic that some criticize Pope Benedict for engaging Marx; whom else would they have him meet, some third-rate contemporary mime? No, Pope Benedict knows that Marx's is a uniquely provocative case for justice at the expense of charity.

According to Deus Caritas Est, "There is admittedly some truth to this argument, but also much that is mistaken" (no. 26). This critical concession to the allegation launches a provocative discussion of the jurisdiction of the church and state in working for a more just social order. "The just ordering of society and the State is a central responsibility of politics," Pope Benedict asserts (no. 28). Indeed, justice is both the origin and goal of the state. But love – caritas – remains necessary even in the most just society (no. 29).

There is so much more to be said about this great encyclical, and I have no doubt Pope Benedict will say more in his subsequent writings. Justice and charity are not opposed – they work together. The conception of the person revealed in Christ and described masterfully by Pope John Paul the Great in Redemptor Hominis remains in the background of his successor's first encyclical. Justice concerns the external relations of men; charity, on the other hand, reaches to the very depths of the person. "Whoever wants to eliminate love is preparing to eliminate man as such," Pope Benedict warns (no. 28). For, as Pope John Paul II wrote, "Man cannot live without love" (RH no. 10).

Joseph Capizzi is Fellow in Religion for the Culture of Life Foundation and Associate Professor of Religion at Catholic University of America.