Laws of Thought

Logic is the tool of philosophy which forms the foundational assumptions for the scientific method. These assumptions form the “laws of thought" that are essential to science and intuitively known by everyone. They are:

1. Law of identity: An object can not have two identities; a tree is not a telephone pole, a dog is not a cat.

2. Law of non-contradiction: A premise can not be both true and false at the same time.

3. Law of excluded middle: Something is or it is not; God either exists or he does not.

I am a Christian, not because someone told me it was true, but because it is a rational system that describes reality. For a system to be rational, it needs to be coherent. Christianity is certainly coherent even if it's premises are disputed. It offers a consistent description of why the Universe exists, its purpose and destinty.

For proof, I offer not only that which can be empirically validated (using the scientific method), but also that which can be logically inferred (using inductive and deductive reasoning) beyond a reasonable doubt. And, while I don't require a belief to be absolutely certain in order to accept it, still, it must be very close. In order for my faith to develop, it must do so on the rock of rationality.

For example, I may not be absolutely certain about my fate after death, but I am so confident (98%) in my belief in the afterlife that the difference is negligible and faith fills in the rest.

And, proof for me is not so much the positive affirmation of a belief but also how it stands up to negative attacks. Or, put another way, my beliefs are not formed by merely finding positive support for them - that's usually very easy - but, they must also withstand attacks to destroy them. In fact, my experience is that beliefs are made stronger by attempts to refute them (or discarded if they fail to measure up).

In the final analysis, when choosing between competing beliefs, the one that offers the most complete description of reality is most often the one that is more reasonable to believe. It is extremely important to understand there are meaningful aspects of the human experience and significant questions that science is not equipped to directly answer. Therefore, one must look to logic to validate or reject a potential belief.

So, the proofs that convinced me of the rationality for God's existence are not solely based on empirical evidence, but also on logical reasoning based on the “laws of thought.”

What is Logic?

Logic is the study of the methods and principles used to distinguish correct reasoning from incorrect reasoning. Author of several books on logic and mathematics, Irving M. Copi wrote, "The distinction between correct and incorrect reasoning is the central problem with which logic deals."

Put more simply, logic is the science of reasoning.

What is reasoning? Reasoning can be defined as a type of thinking in which an inference occurs.

What is an inference? An inference is the process of drawing a conclusion from a one or more propositions which are either true or false.

What is a proposition? A proposition is merely a sentence that is either true or false.

Propositions are grouped to form arguments. An argument is a group of propositions, one leading to the next, that results in a conclusion.

Arguments, then, are structured forms of reasoning.

Arguments can be deductive or inductive. In a deductive argument, the conclusion necessarily follows from the propositions. For example:

All humans are mortal.
Socrates is a human.
Therefore, Socrates is mortal.

Deductive arguments are evaluted as either valid or invalid. This is important to understand because deductive argument can be valid but untrue. For example:

All humans have 3 legs.
Roy is a human.
Therefore, Roy has 3 legs.

The argument above has a valid form but its untrue premises render it invalid.

An inductive argument proceeds from specific observations to a general conclusion. For example:

All cows are mammals and have lungs.
All dogs are mammals and have lungs.
All cats are mammals and have lungs.
Therefore, all mammals (probably) have lungs.

Unlike the deductive argument, in an inductive argument, the propositions provide support for the conclusion, but the conclusion doesn't necessarily follow. Inductive arguments are evaluted as better or worse based on the strength of their propositions.

So, in conjunction with the Laws of Thought, the task of the logician is to:
1. Identify the form of the argument
2. Determine the validity of the deductive argument
3. Evaluate the strength of an inductive argument.

References:
Irving M. Copi, Introduction to Logic, 7th ed. (New York: Macmillan, 1986)
Geisler, Norman L., and Frank Turek, I Don't Have Enough Faith to be an Atheist, Crossway Books, 1300 Crescent St., Wheaton IL 60187, ©2004.