Example of a bad argument: Religion entails the worship of God. Most violence in the world is caused by religion. Violence, however, is incompatible with the concept of a benign “God is love” divinity. Therefore, religious violence is evidence that God does not exist.
(The first premise is true, but the second is false, the third is ambiguous [i.e., “violence” is open to multiple meanings, such as man-caused physical violence, the violence of nature and the elements, etc.], and the conclusion does not logically follow from the premises.)
Kreeft explains these elements thus: “A term answers the question what it is. A proposition answers the question whether it is. And an argument answers the question why it is.”
Statement/Proposition: “A sentence that is either true or false … typically a declarative sentence or a sentence component that could stand as a declarative statement.”16 The essence of apologetics is evaluating, critiquing, and demonstrating either the truth or falsity of statements/propositions made about God and His revelation to the world, as well as about everything that pertains to those “meta subjects,” including the Bible, Apostolic Tradition, the Church, the sacraments, et cetera. For example,
• God exists.
• Mary did not have other children besides Jesus.
• The sacrament of Baptism regenerates the soul of the one baptized.
• The Bible does not teach the principle of sola scriptura.
Kreeft adds a further precision: “A proposition has two structural parts: the subject term and the predicate term. The subject term is what you are talking about. The predicate term is what you say about the subject. The word “subject” and “predicate” mean the same thing in logic as in grammar.17
Premises and Conclusions: “The statements that set forth the reasons or evidence, and … the statement that the evidence is claimed to support or imply…. [T]he conclusion is the statement that is claimed to follow from the premises.”18 In any argument, one or more of the premises must make a claim that it seeks to prove or infer explicitly in the conclusion, which is indicated with words such as “therefore” and “thus.”
Premise: Jesus Christ, who is God incarnate, promised that the gates of hell will not prevail against the Church.
Premise: God cannot lie.
Conclusion: Therefore, the Church Christ established will never totally apostatize.
A claim can also be logically inferred implicitly through premises, for example, in this way:
The earliest Christians clearly understood what Jesus meant by saying, “This is my Body” and “This is my Blood” at the Last Supper.
The Apostles explained to the earliest Christians all that Jesus said and did and what he meant by what he said and did.
The Apostles knew what Jesus meant by what he said and did because they were eyewitnesses to this event and because Jesus explained everything to them (see Matthew 13:36, 16:5–12, Mark 4:34).
The next component is validity. For an argument to be sound, it must have clear terms, true premises (i.e. claims), and valid logic, in which case the conclusion will necessarily follow. Here are two examples of valid arguments, beginning with a classic formula:
All men are mortal.
Socrates is a man.
Therefore Socrates is mortal.
All two-dimensional shapes that have three sides are triangles.
This two-dimensional shape has three sides.
Therefore this two-dimensional shape is a triangle.
Hypothesis: “A proposition, or set of propositions, set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation (working hypothesis) or accepted as highly probable in the light of established facts.”19 An example of this is the hypothesis that Jesus physically rose from the dead. This proposition adequately explains why the Apostles and hundreds of others would not only proclaim that they were eyewitnesses to his Resurrection but would also be willing to suffer and die as martyrs for this conviction. The alternative hypotheses to the Resurrection, incidentally, cannot adequately account for this phenomenon.
Different Approaches to the Truth
Deductive and Inductive Reasoning: The deductive approach to apologetics involves starting with general principles and working toward a specific conclusion. If the premises are true and logic is valid, the conclusion is inevitably true.
Also called “top-down” logic, deductive reasoning moves from one or more general statements (premises) to reach a logically certain conclusion. When properly formed (i.e., valid), if the premises are true, the conclusion must also be true. The earlier examples of arguments don’t have necessarily true conclusions even though their premises are true because the conclusion necessarily goes beyond the premises, which is the very reason why we use those arguments. But a valid deductive argument only makes explicit what is already contained in the premises.
All As are green.
All Bs are As.
Therefore, all Bs are green.
If the premise(s) is false, the logic can still be valid, though the conclusion would likewise be false. For example, it could be that, in fact, some As are red, in which case the first premise (“all As are green”) would be false.
All Catholics are hypocrites.
William is Catholic.
Therefore William is a hypocrite.
The Inductive Approach: The fictional detective Sherlock Holmes is known to countless readers as a genius for figuring out obscure and complex crimes on the basis of drawing conclusions from minute and easily overlooked details. He exemplifies the inductive reasoning approach. The popular television show Monk is another example of inductive logic at work.
Examples of inductive reasoning in apologetics would include:
1. Tabulating all the times Simon Peter is mentioned by name in the New Testament (195 times), and then comparing that statistic to the number of times the next most often mentioned Apostle is named (John, 29 times), suggests that Simon Peter was the most prominent figure among the Twelve Apostles.
2. Noting that things continually come into and go out of existence and are therefore contingent (i.e., unnecessary) and do not have to exist because at one point they did not exist. But yet they do exist. This suggests that there must be a being, which we call God, who must necessarily exist in order to explain the existence of this vast number of contingent, unnecessary beings.
3. Examining all the details of the life of Jesus Christ as they are presented in the pages of the New Testament — his miracles, teachings, reading the secrets of the heart, claims to be God, claims to forgive sins, and rising from the dead — so as to draw the conclusion that he is in fact truly God and not merely a man.
The Apophatic Approach: From the Greek ἀπόφασις (apóphatis), meaning “denial.”20 The apophatic approach uses negation to arrive at a clearer understanding of the truth. By asserting things that are not true, you can clear away erroneous and misleading claims that deny or obscure the truth. Examples of true statements that are expressed negatively in order to eliminate erroneous alternatives:
• God is not evil; He is not limited; He is not subject to change.
• God is not the author of evil.
• Human beings do not have the natural ability to save themselves from damnation.
• The Holy Spirit