The uses of the word, “logic.” “There “are four senses (definitions) in which the word logic is used: (1) at the theoretical and symbolic level is a comprehensive term that refers to sets of axiomatic relationships, ‘an analysis and evaluation of the ways of using evidence to derive correct (true) conclusions,’ (2) in common speech at a nontechnical level is a synonym for words such as ‘workable,’ ‘reasonable,’ and the like a logical plan may be a workable plan, an illogical step may be a rash step; (3) (in) a formal presentation of an argument: that is, people engage in ‘logical argument,’ whether or not there are fallacies in the steps (that) they take; and (4) in common speech may refer to a set of propositions or even an outlook which may or may not be ‘logical’ in the first sense.” (D. A. Carson, Exegetical Fallacies, Baker Academic Books, 2nd edition, pp. 87-88,)

Ed’s Comments on These “Senses” of the Word, “Logic”

The reader should note that #1 represents logic in its formal sense. Many people are not familiar with this use. It entails propositions (statements of facts) from which conclusions are drawn. One should look at book on logic to see how these propositions may be stated and how conclusions are drawn from them. Certain arguments may be proven to be infallibility true, or to the contrary, may be proved erroneous.

A better name for #3 might be “rational” thinking, as it does not involve the formal steps of logic, but an attempt at clearly drawing one conclusion from other facts and statements. What is reasonable or rational is rarely formally “logical.”

#2 and #4 may include almost any kind of reasoning in serious or casual conversations. It is doubtful that “logic” should be used for this process at all, as it hides the important use of formal logic.

It is most important that readers understand that there is a discipline of formal logic because it stands in stark contrast to all the other definitions. Formal logic can start with true statements (premises, axioms, presuppositions, etc.), and if the process of logic is applied correctly, then the conclusions are also true.

For example, The Trinity is common to all those who profess true Christianity, yet “trinity” does not appear in the Bible. The logical steps are these:

Only God is omniscient, omnipresent, and omnipotent.

The Father, Son, and Holy Spirit all have these attributes.

The Father, Son, and Holy Spirit are persons.

There is only one God.

Therefore, the Father, Son, and Holy Spirit are One God and Three Persons.

“Trinity” is an arbitrary choice of a word to apply to this conclusion. The word itself does not make its own concept true. The concept of Trinity is a logical conclusion from the premises which are absolutes. So, the conclusion argued logically is as true as its premises. All the steps, as a whole, is called a syllogism.

The reader may need to wrestle with this process. It cannot be done apart from reviewing at least the first few chapters of a book on formal logic. A failure to understand the use of formal logic will greatly hamper one’s attempts at a Biblical worldview.

The phrase “mere human logic” shows ignorance of the process of formal logic and its power to reason to truth from true propositions.

For the process of formal logic, see