CFS-WB-CH04

Chapter 4
Aa
VOCABULARY
Philosophy: The study of
ultimate reality and its causes
by human reason alone. From
the Greek word philosophia,
which means “love of wisdom.”
Five Ways: Five arguments
developed by St. Thomas
Aquinas that use human
reason and observation of the
created world to conclude that
God exists. Also called the
“five proofs for the existence
of God.”
The Love of Wisdom
The term philosophy comes from the Greek word philosophia, which
means “love of wisdom,” but is commonly used today to mean “worldview.”
For example, you may have been asked, “What is your philosophy
of life?” That modern meaning is not how we are using the word here.
Instead, we will use its actual meaning: a reasoned study of the truth of
things.
The great Medieval philosopher St. Thomas Aquinas believed that
philosophy could tell us a lot about God. St. Thomas is famous for using
logical reasoning to prove God’s existence: there must be one uncaused
being which created everything else — and this reality is referred
to as God. Using his “Five Ways,” or five proofs for God’s existence, we
can simply look at the world around us and, by using reason, conclude
the existence of the Creator.
Before we delve into the arguments themselves, it would be beneficial
to understand what a philosophical proof is and how it works. To
begin, bear in mind that philosophical proofs function differently than
the scientific method, which relies upon empirical data and experimentation
for proof. Philosophical proofs depend upon logic as well as formulated
premises, which are readily verifiable or proven by a prior argument.
For a philosophical proof to be valid (true), the logic must be
sound, and the premises of the argument must be verifiable in some
way. Philosophical proofs can be challenging to understand, but they
are valid even if we may not fully comprehend them. The same is true of
the scientific method. For example, just because one does not understand
the law of thermodynamics does not mean the law does not exist.
The same is true when it comes to proving God’s existence.
The most basic structure of a philosophical proof has two premises
and a conclusion. We call the first premise the major premise, and
the second the minor premise. A proof ends with a conclusion that
follows logically (in other words, it must be true) from the rational coherence
of the two premises. If the premises are true, the conclusion
must be true. The conclusion can then become a premise to another
proof, and so on.
Armed with this understanding of how a philosophical proof works,
let us now turn specifically to Aquinas’ Five Ways and a more modern
argument for God’s existence.
70 Apologetics I: The Catholic Faith and Science
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