The most successful medieval attempt to compile
an integrated and systematic Christian philosophy
is Saint Thomas AQUINAS’s Summa Theologica
(Summa [or Compilation] of theology). Aquinas
began the Summa in about 1265, and left it unfinished
upon his death. In it, he attempts to reconcile
Christian theology with Greek philosophy, in particular
the philosophy of Aristotle. For this task,
he was able to rely on new Latin translations of the
philosopher made by his fellow Dominican friar
William of Moerbecke.
Aquinas indicates that his Summa Theologica
is intended as an orderly synthesis for beginning
students of Christian theology (thus it is not intended,
for example, as an argument addressed to
nonbelievers). It reiterates some of the ideas from
his earlier and less systematic Summa Contra Gentiles.
To some extent, Aquinas is countering some
of the issues raised at the University of Paris in the
13th century by the study of the Muslim philosopher
AVERROËS’s commentaries on Aristotle. These
ideas, particularly Averroës’s denial of individual
immortality, had led to the doctrine of the “double
truth,” that certain things might be proved true
by reason, but that their opposite should be believed
true as a matter of faith. For Aquinas, truth
was indivisible, and the truth of philosophical reason
must be in accord with the truth of divine revelation.
The Summa demonstrates that human
reason can prove some of the tenets of faith, such
as, for Aquinas, the existence of God; reason can
also illuminate some of the truths of faith that
cannot be proven; and sometimes, the assumptions
of philosophers that contradict those of faith
can be shown to be unsupported by reason.
Thomas divides the Summa into four major sections:
part one deals with questions of sacred doctrine,
the unity of God, the holy Trinity, the created
world, angels, the six days of Creation, man, and on
divine government. The first part of the second part
considers questions of man’s end, human actions,
passions, habits, vices, and sins, followed by questions
of law and of grace. The second part of the second
part reflects on the theological virtues of faith,
hope, and charity, the cardinal virtues of prudence,
justice, fortitude, and temperance, and finally acts
pertaining to certain men. The incomplete third
part looks at the incarnation and the life of Christ,
the sacraments of baptism, confirmation, communion,
penance, extreme unction, holy orders, and
matrimony, and ends by considering the resurrection.
The complete Summa comprises 38 tracts divided
into 631 questions, subdivided into about
3,000 separate articles.
Each individual article of the Summa follows the
dialectic method advocated by the scholastic
philosophers of the high Middle Ages. The article is
worded as a question, such as, for example
“Whether the Natural Law Can Be Changed?” (the
fifth article of Question 94 in the first part of the
second part). For each article Aquinas first enumerates
some “objections,” or arguments against
his own position, such as “the slaying of the innocent,
adultery and theft are against the natural law.
But we find these things changed by God: as when
God commanded Abraham to slay his innocent
son” (Thomas Aquinas 1947, I, 1011).He then says
“On the contrary,” and cites a quotation that supports
his own view, usually from the Scriptures,
from Aristotle, or from one of the church fathers
like St.AUGUSTINE. In this particular article, he cites
the Decretals (the most influential work of medieval
canon law) as saying “The natural law dates
from the creation of the rational creature. It does
not vary according to time, but remains unchangeable”
(Thomas Aquinas 1947, I, 1012). He always
follows this assertion by the main body of his argument,
beginning with the phrase “I answer
that. . . .” Finally, he ends the article by explicitly
countering each of the opposing arguments with
which he had begun the question; for example, his
reply to the above objection, while somewhat
lengthy, ends with the contention that “in natural
things, whatever is done by God is, in some way,
natural” (Thomas Aquinas 1947, I, 1012).
Although several of its conclusions were officially
condemned by the church in 1277, shortly
after Aquinas’s death, in subsequent centuries the
Summa Theologica became essentially an expression
of the official theological position of the
Roman Catholic Church. It remains to this day the
most influential book of its kind ever written.
Bibliography
Clark, Mary T., ed. An Aquinas Reader. Rev. ed. New
York: Fordham University Press, 2000.
Davies, Brian. Aquinas. London and New York: Continuum,
2002.
Eco, Umberto. The Aesthetics of Thomas Aquinas.
Translated by Hugh Bredin. Cambridge, Mass.:
Harvard University Press, 1988.
Thomas Aquinas, Saint. Summa Theologiae. Cambridge:
Blackfriars, 1964ff.
———.Summa Theologica. Translated by the Fathers
of the English Dominican Province. 3 vols. New
York: Benziger Brothers, 1947.
Malene A. Little