Philosophy, it has been said, is the handmaiden of theology.  “It is,” Pope Leo XIII said, “the bulwark of faith and the strong defense of religion” (Leo XIII, Aeterni Patris (AP), 4).  Form the seminal moments of the Church, great theologians like St. Paul and Justin Martyr relied on philosophy to bring the revealed truths down to a level that was intelligible to mankind.  For this reason the Church has always encouraged the study of philosophy, submitting each of the various schools to her wise judgment according to “the excellence of faith, and at the same time consonance with the dignity of human science” (AP, 2).

The Church has long held that Scholasticism, put forth most prominently by St. Thomas Aquinas, is the most useful of all the philosophical schools for understanding and defending the Faith.  While the Church may not have an “official” philosophy, the philosophy of St. Thomas is as close as it comes.  It is his moderate realism that forms the Church’s foundational understanding of the knowledge of God, the Trinity, the Sacraments, the Incarnation, Sanctifying Grace, and much else.

The Problem of Universals

Moderate realism is a school of thought that treats the question of universals.  In our quotidian experience we encounter many individual things—a car, a smartphone, a cat, a neighbor.  Yet in encountering those things we also see that they relate to other things that are like it.  We call it a car, for example, because it belongs to some species of cars that all share some particular nature.  They may have differences such as color and body shape, but we still recognize them as cars.  We do this because we posit there is some universal essence that makes them all cars.  Through the power of abstraction, the mind is able to separate the essence of the thing from the individual instance of it.  One of the perennial problems in philosophy is where exactly this universal essence exists.

A realist, like Plato for example, would say that the universal does exist outside the mind.  It exists in some world of universals (this is the allegory of the cave) and that all the cars, phones, cats and people we see here are mere shadows of that universal.   Many early Christians were affected by Platonic thinking.  It also led to many heresies because of its sharp separation between the material and non-material realms.

Like Platonic realism, Thomistic moderate realism says that the universals do exist outside the mind, but they exist in the things themselves.  In fact these universals give form, that is, they make the individual thing what it is.  The form is one thing, but what makes it individual is its matter.  All of the sensible properties of things are the product of matter limiting form.  With its matter/form distinction the Church is able to develop her entire understanding of the Sacraments, most especially the Eucharist.

There is a third approach to the problem of universals that is mostly a reactionary position to the moderate realism of the Scholastics and this is nominalism.  Nominalists posit that universals do not exist.  These universals or ideas are merely sense impressions that we group together for convenience.  Only individual things exist.  So, rather than examining esoteric questions like how many angels can dance on the head of a pin, these medieval philosophers said there was no such thing as pins and angels.  What practical import could this have?

Nominalism was not just a reaction against realism, but a reaction against reality.  If there are no universals then there is no power of abstraction in man.  If there is no abstracting power then sense knowledge and intellectual knowledge become redundant, both grasping the same object—the individual.  This leads to both the angelism of Descartes and the materialism of Locke.

With nothing to be abstracted, the outside world has nothing to tell us.  The universe is just a collection of individual things with no real relation to each other.  The focus of philosophy, where it still existed, was towards interpreting man’s interior convictions (“I think therefore I am”).  With no natures there is no good or evil in the leading to voluntarism.

Still, even if we grasp some of the unintended consequences, what does this have to do with theology?  Natural theology, that is what can be know about God using human reason alone, ceases to exist as a field of inquiry.  The book of creation is closed leaving faith and Divine revelation as the only means of knowing about God.  Fideism and agnosticism rule the day.  God Himself becomes distant and capricious, no longer being the Logos but instead pure will.

A Famous Nominalist and His Legacy

One can begin to see just how profoundly nominalism has infected modern thought.  Nevertheless, it is instructive to examine just how nominalism escaped the medieval classroom and was smuggled into everyday thinking.  It was through the most famous nominalist, a man who was more famous than the founder William of Ockham, Martin Luther.  It was, as Fr. Louis Bouyer says in his book The Spirit and Forms of Protestantism, through the Reformation that nominalism escaped from the theoretical playground into the pulpit and the public square.

Luther’s early efforts at reform were based on some positive principles that the Church would readily agree with—sola fide and sola gratia for example.  It is when these principles were fertilized by the manure of nominalism that they became revolutionary.

Recall that nominalism posits that there are no real relations between things.  God is completely Other and although He might give us gifts, they cannot really be ours.  Faith, which Catholics believes comes as a gift in Baptism (thus the necessity of Baptism), when seasoned with nominalism becomes something we have on our own.  As long as we believe we are saved then we are saved.  Right belief, according to this view, in order to be truly ours must come from the heart and nothing from the outside (like Baptism) can possibly bestow that upon us.

So too with sola gratia.  Catholics believe that we are saved by grace alone.  Sanctifying grace is infused into our souls making us “partakers of the divine nature” (c.f. 2Peter 1:4) so that we share in Christ’s sonship and truly become children of God (1John 3:2).  Nominalism poisons sanctifying grace making it an impossibility.  Participation in God’s nature is not possible because grace that produces a change in us, while still remaining the Grace of God is non-sensical.   The conclusion is that although salvation is a free gift, it is only insofar as God declares us righteous rather than actually making us so.

Understanding the philosophical roots of Protestantism can help us to bridge the gap with our separated brethren.  We are separated because we are living in different realities.  The Reformation, to be a true reformation should have swept away nominalism.  Instead we are living among its intellectual progeny and need to understand that although we often use the same vocabulary, we mean very different things.  Pointing out the errors of nominalism should be a start to any ecumenical dialogue.