This essay is not a reflection on C.S. Lewis's The Great Divorce, which discusses the great divide between good and evil, heaven and hell.

Nor is it a commentary on the marital split that often occurs between husband and wife. It is about a wholly unnatural divorce, surely of great magnitude, between Catholicism and politics.

This great divorce, in truth, does not exist within Catholicism itself, but secularists and misguided Catholics (not excluding Canada's prime minister) argue passionately that it does. At the root of this divorce is the erroneous and invidious assumption that Catholicism is built purely on faith and has no basis in reason, that universal faculty all human beings share.

This is a divorce that characterizes Catholics as aliens with regard to the political scene, as irrelevant and annoying intruders who are trying to impose a private faith onto a rational public.

The assumption behind this great divorce is so deeply entrenched, as if evidenced in the media, that it is neither discussed nor considered. As a result, it lingers on, depriving Catholics of their full role in the democratic process.

For example, a secular journalist will ask “the man on the street” whether he thinks the Catholic Church should dictate how society should think about abortion, same-sex marriage and other contentious issues, or whether the people should decide for themselves on the basis of facts, experience, reason and science.

What the educated Catholic must realize is that his Church is not based solely on faith.

Not only does reason play an essential role in the formation of his Catholicism, but also, as history has shown, the Catholic Church from its inception has consistently been a world leader in the realm of philosophy and science.

The first step in becoming a Catholic (or Christian) is to be a humanitarian, which is to say, to have an abiding concern for all human beings. Christ commands his flock to love their neighbors. It is this humanitarian ground, coextensive with the human race, that gives Catholics a particular relevancy in the world of politics.

The language of Catholic philosophers has, from their earliest rumi-nations, bristled with words such as rights, justice, dignity, freedom, equality and so on. This is not the language of an alien group of fideists. It is the language of Catholic thinkers and activists who are deeply involved in the essential needs of all human beings.

It was largely through a Christian impetus that infanticide, slavery, racism, unjust incarceration and other crimes against humanity have been strongly denounced and, in some cases, overcome. Catholicism is grounded in humanitarian interests and is crowned with articles of faith that deepen but do not contradict them.

St. Thomas Aquinas referred to these principles that can be known by all men as “preambles to the faith.” St. Augustine held that one should not adhere to any interpretation of the Bible if it should prove to be false, lest holy Scripture be exposed to the ridicule of nonbelievers and obstacles be placed in the way of their believing.

In order to understand that abortion is fundamentally a crime against humanity, one need not be a Catholic but only a human being with a basic interest in the welfare of his fellow human beings. The same can be said about marriage. Marriage is a social institution that is grounded in a personal love and commitment that subsumes the biological, which, in turn, includes the physiological, procreative and immunological dimensions of the human being.

Because this interpersonal, biological alliance can be elevated to something sacramental does not exclude the firm and undeniable realities that under-gird it. Nor does it discredit what faithful Catholics have to say about marriage.

Catholics have plenty to say about the nature of marriage without calling upon any articles that are peculiar to their faith. The Catholic Church, as a matter of fact, has been history's preeminent champion in honoring marriage and the family as the basic unit of society. It has staunchly defended the rights of family members against exploitation either from the workplace or by the government. It has consistently taught that the basis of ethics is anthropology.

The truth that the Catholic Church grounds itself in what can be known and imitated by all men cannot be kept a secret from everyone.

Phyllis Chesler, for example, hardly a friend of Christianity, was struck by the broad, humanitarian basis for the Church's document on bioethics, Donum Vitae (Gift of Life).

In her book, Sacred Bond, in which she argues passionately against surrogate motherhood, she makes clear her admiration for the Church's approach: “I still admire the spiritual context in which the Vatican discusses surrogacy. All life is sacred; ends never justify the means. Reproduction and genetic experimentation do not exist in a moral vacuum. When they do, they exploit the many for the sake of the few.”

Feminists flinch when I say I respect the “seamless garment” of logic worn by the Vatican. But why should my recognition of the Vatican's consistency imperil my feminist credentials? Do I have to agree with my comrades on everything and with our “enemies” on nothing?

The Catholic faith attempts to embrace everyone. Its theology is not without a supporting philosophy. The secularists and misguided Catholics who attempt to disenfranchise Catholics from the political process usually end up by opposing what is truly reasonable while imposing their own faith agendas. But here faith is uprooted from reason and becomes an arbitrary ideology that is not possible for all human beings to share.

Let it be known — and known well, particularly among Catholics — that Catholicism is a whole, consisting of reason and faith, politics and religion, the mind and the heart. The “great divorce” is a myth. And it is a most pernicious one. There should be no separation between Catholicism and politics.

Calgary's Bishop Fred Henry was absolutely right when he stated, “The mantra of ‘separation of Church and state' in our Canadian context is simply a crass secularist attempt to discount and marginalize persons with religious faith.”

Donald DeMarco is professor emeritus at St. Jerome's University in Waterloo, Ontario.