Both "Fact" And "Form" Are Essential
In The recent Deaver-Holt Debate evidence was introduced and the following letter from a professor from the University of Texas was a point of difference. The letter: "Mr. ______ has consulted me about a syllogism which was provided and which he questioned. I am afraid that I must agree with Mr._______ that your 'syllogism' is no syllogism at all. The fallacy involved in your argument is that you assume in your major premise the very point to be proved. If you begin by saying that 'all passages which authorize the performance of purely religious works are passages which apply with equal force to the church and the individual,' then it is obvious that if you find any which mention religious works, you will decide these apply to both the church and the individual. You must prove your major premise."
I must admit that I am probably not the world's best expert in the field of logic, but I do wish to comment on the statement from the professor from the University of Texas. I believe our learned professor confuses us on the difference between formal and material validity. Logic is the science of sound reasoning. The truthfulness of a conclusion of a reasoning process depends upon (I) the data in the propositions and (2) the validity of the process itself which is the syllogism form.
Most of us understand the syllogism as a tool or device in the science of reasoning and common sense, which sometimes is not so common. The syllogism as a tool is called formal logic. The formal logic accepts the material or data as being truth.
The valid syllogism or formal logic contains two propositions that a conclusion may be reached. When stated in normal order, the first of these constitutes the major premise; the second, the minor premise; and the third the conclusion. Secondly, a valid syllogism or formal logic must contain three and only three terms. The term which is contained in both premises is known as the middle term; the predicate of the conclusion is the major term; and the subject of the conclusion is the minor term. Thirdly, the term which appears twice in the premises (that is, the middle term) must be fully distributed in at least one of the premises.
Again, a syllogism or formal logic is a formula by means of which two independent terms are compared through the office of a common middle term. As is true of most formulas, the syllogism is largely indifferent toward the subject matter with which it deals. It is concerned about formal logic, not which data or material. It accepts these as being true. Therefore, it does not in any sense guarantee the material (data) is true or false. The material or data in the premises may be false but the syllogism form true.
To illustrate; No. 1:
1. All Baptists are Methodists 2. Tom is a Baptist
Conclusion: 3. Tom is a Methodist Again in No. 2
1. All ministers are Republicans 2. I am a minister
Conclusion: 3. I am a Republican According to the formula or logic, we have here perfectly valid syllogisms. Yet all of us realize that in each of the major premises the material or data is incorrect according to fact. But according to our tool of formal logic, the conclusions are correct. These premises must not be denied or attacked on formal logic. They should be at and denied not on syllogistic form but on material validity.
It should be also understood that the data or material in each proposition may be true but the formal conclusion be false.
To illustrate:
1. All Baptists are baptized 2. All members of the church are baptized
Conclusion: 3. All members of the church are Baptists No conclusion can be drawn by formal logic in this example. Both the major and minor premises are true, but the conclusion is false.
Our learned professor was asked if the syllogism of formal validity was correct. He should have answered "Yes" but might have pointed out that the material of the propositions themselves needed to be proved. But hear him again, "The fallacy involved in your argument is that you assume in your major premise the very point to be proved.... You must prove your major premise." Certainly so. The debater must carry the burden of proof on both major and minor premises. If brother Deaver could prove his material in each of the major and minor premises, this learned professor no doubt would agree that the formal syllogism is valid. But instead of the professor admitting the formal syllogism was true, he himself wanted to get into the debate by denying the material validity of the proposition. This confuses the hearers.
The problem of formal and material validity must, therefore, be divorced in our evaluation of the probative force of any particular piece of syllogistic inference. Formal logic must be tested by the rules and corollaries peculiar to the syllogistic form; the material validity is subject to the test of reality and determined by authority. In his case, "what do the scriptures authorize?"
— 2303 Franklin, Nederland, Texas