In January 1988, Cardinal Joseph Ratzinger, then at the height of his notoriety as “God’s Rottweiler”, arrived at Cambridge University’s Catholic chaplaincy to give the annual St John Fisher Memorial Lecture.

A Polish-Canadian card-carrying atheist, whom I got to know some time later, attended. He wangled his way into being one of the select few to be invited to the post-lecture dinner in the chaplain’s oak-panelled dining room. Never short of chutzpah, he nabbed a seat right beside the cardinal.

Midway through the dinner, Ratzinger turned towards our friend, Leszek. Holding him firm with a beatific smile and a deep gaze straight into his eyes, the cardinal said softly: “They tell me you’re an atheist...”

Leszek was a big, ebullient, bearded bear of a man, 33 years old, with a spell in the army behind him. He was given to declaim his opinions deep into the night and you needed his industrial quantities of self-confidence, audacity and tirelessness to resist him.

Yet, when Leszek told me the story, he described how Ratzinger effortlessly disarmed him. He was rocked back by the direct question and, simultaneously, pulled in by the seductive charm. He remained an atheist but he carried the encounter with Ratzinger within him.

When the former pope is buried today, we can be sure we will hear more about the legendary charm, directness and genuine interest in dialogue with people of other faiths and none.

But we will also hear about a very different man, seemingly ready to put dogma above love and personal consideration. This will be the “conservative” man contrasted with his younger “liberal” successor, Pope Francis.

It’s Ratzinger who denounced legal cohabitation as “the legalisation of evil” and who compared the “evil” of gay marriage to ecological destruction.

It’s the Vatican II theological adviser who ended up investigating other theologians for heresy. It’s the liturgist who discouraged rock masses while permitting the celebration of the pre-Vatican II Tridentine liturgy and seeking to mend fences with Vatican II rejectionists.

These contrasts call for explanation. Calling him a “conservative” creates confusion, unless we disentangle the word’s four different senses.

First, Ratzinger was a political conservative in the sense understood in post-war Bavaria, where scepticism about social “progressivism” goes hand in hand with a belief in the social responsibilities of the state to foster solidarity and economic corporate responsibility.

Pope Francis only seems different, here, because he’s addressing the ecological limits of economic globalisation. But the work on the encyclical that tackles ethical global development began, in fact, under Benedict XVI.

This social conservatism is suspicious of sweeping diktat whether from the right or the left. Ratzinger was raised by an anti-Nazi father. One of his cousins was a victim of the Nazi eugenics programme. One of his favourite teachers was imprisoned at Dachau.

The man who denounced the “dictatorship of relativism” was someone who saw mortal danger for a humane society both in Nazi claims of a super-race and in 21st-century claims that morality is a purely human or cultural construction.

He did not call them all “evil” to equate them. Lying, too, is “evil” but that doesn’t mean liars are as bad as Hitler. “Evil” is the word used by moral theologians to indicate that something cannot be justified under any circumstances.

Second, Ratzinger was a theological conservative. It’s an identity compatible with his decision to resign as pope. Back in 1971, a theologian he much admired, Hans Urs von Balthasar, raised the idea of temporary popes (“after all, why not?”).

When you’re a member of a 2,000-year-old institution, going back to the sources can be deeply subversive of assumptions that are merely hundreds of years old. Ratzinger’s “subversiveness” was noticed by his pre-Conciliar religious superiors, who had a shallower sense of Church history.

Calling him a ‘conservative’ creates confusion- Ranier Fsadni

Third, he was a conservative in ecclesiastical politics and pastoral policy. It is on issues of authority and the nature of the hierarchy that Ratzinger differed most from “liberals” like the late Cardinal Carlo Maria Martini.

However, like Martini, who pioneered public discussion with eminent non-believers in Milan, Ratzinger believed that to be a Christian is to be open to everyone and, in a mysteriously real way, meet Christ.

If that doesn’t sound compatible with being “God’s Rottweiler”, it’s because Ratzinger’s openness to dialogue was combined with the conviction that you couldn’t truly encounter someone and keep your beliefs in the background.

For him, doctrines didn’t get in the way – they opened the way. Think of his fleeting encounter with Leszek, the Cambridge graduate student. He had, famously, public dialogues with atheists such as the German philosopher, Juergen Habermas and the Italian politician, Marcello Pera.

Because he believed Christ was the Logos, he also believed that, where reason is to be found, truth that is compatible with Christianity can be discerned.

But that’s also why he believed that, without a Christian foundation, liberal rationalism ended up with an irrational foundation. For him, preserving doctrinal purity was the way to preserve the foundations of reason.

That conviction enabled him to be a clear-eyed critic of the wishy-washy versions of ecclesiastical liberalism. Faced with claims that enabling priests to marry would eliminate the problem of fornicating priests, for example, he retorted that it would create the problem of adulterous priests. His conservative view of human weakness could be bracing.

Finally, although a daring thinker, he was conservative in his methods. His understanding of culture and civilisation remained rooted in 19th-century German scholarship.

He seemed innocent of late 20th-century philosophical and cultural anthropology – including of highly innovative Catholic scholars like Michel de Certeau, Charles Taylor and Bruno Latour.

As a result, he thinks about culture in terms that don’t quite fit the mobile global civilisation we live in. He can see the false promises of neoliberal globalisation but less so those based on nostalgia for a past to which we can’t return. He credited the boundaries between historical agrarian civilisations with more reality than they have today.

Ratzinger’s conservatism is complex. The four kinds of conservatism he represented don’t have to be chained together. His position as one of Catholicism’s leading 20th-century theologians may well be enhanced if one or two parts are disentangled from the rest.