It's Hogwash To Say Deductive Arguments Produce Certain Conclusions While Inductive Arguments Are Weaker by Comparison!!

Johannes Y K Hui recently claimed something odd:

(1) Every SOUND deductive argument’s conclusion is impossible to be false. [A sound deductive argument would be one that has all true premises and a valid form/structure. A sound deductive argument/reasoning would produce a conclusion that is impossible to be false; such a sound deductive conclusion would be guaranteed true with 100% certainty.]

(2) Every cogent/strong non-deductive argument’s conclusion is possible to be false. [In contrast, a cogent/strong non-deductive or probabilistic argument at best produces only a conclusion that is only probably true; its conclusion is always possible to be false.]

Because of the above, when the conclusion of a non-deductive or probabilistic argument contradicts that of a sound deductive argument, the conclusion of the non-deductive argument would be guaranteed false with 100% certainty.

Given the above two points, because there exists sound deductive arguments that produced the conclusion that “the God of Classical Christian Theism exists extramentally” (which would be guaranteed to be true with 100% certainty given the nature of SOUND deductive arguments), any non-deductive argument (such as all those evidential probabilistic arguments making use of the existence of sufferings) that concludes with “the God of Classical Christian Theism probably does not exist extra-mentally” would be totally negated.

As a former college instructor in logic and critical thinking who taught students who were police officers, detectives, and lawyers, allow me to teach you something useful. The only thing certain in a valid deductive argument is the logical structure of the argument itself. Many philosophy novices fail to get this point.

Take this deductive argument:

If the moon is made of green cheese then Elvis is still alive.

The moon is made of green cheese.

Therefore Elvis is still alive.

We can know with certainty that the logical structure of this argument is a valid one, since its form is known to be modus ponens. But is it a sound argument where the premises are also true? Of course not! Not even close! At best then, all we can know with certainty about a deductive argument is whether it's valid or invalid. But don't let that fool you. While it's definitely a great beginning, it doesn't say anything else important. A valid argument is still a valid one, regardless of whether the premises are false. An invalid argument is still an invalid one, regardless of whether the premises are true. This is because the concepts of "valid" and "invalid" are based on the logical form of the arguments themselves.

Take this invalid argument:

If it is raining then it is wet.
It is wet.
Therefore it is raining.

The premises can both be true but it's an invalid argument, known as Affirming the Consequent [Look it up].

The concepts of “true” and “false” only apply to the premises. The premises in an argument are not valid or invalid, sound or unsound. The concepts of “valid” or "invalid" only to the logical structure of the deductive argument itself. The concepts of “sound" and "unsound" only apply to the deductive argument as a whole. An argument is "sound" if it has a valid logical structure and also contains true premises. An "unsound" argument contains an invalid logical structure, or at least one false premise, or both an invalid structure and at least one false premise. A deductive argument in and of itself is neither true nor false, nor valid or invalid.

Now let's consider this valid argument instead:

If it is raining then it is wet.
It is raining.
Therefore it is wet.

How would we know the premises are true? I can imagine some scenarios where this would not be a sound argument if we were talking about being inside a house [Contexts sometimes must be stated]. But granting the right context how would we know it's true? By induction not deduction. By experience not crunching numbers. One cannot deduce ourselves into knowing any matter of fact by deduction (per David Hume). But with induction comes different degrees of probabilities. So all claims about matters of fact depend on induction about which no one can be certain.

At best then, a valid deductive argument having true premises is only guaranteed (but not certain) to be sound. A sound deductive argument does not indicate any probability to its soundness, other than that the premises are more probable than not to be true.

My point is that a sound deductive argument doesn’t provide a certain conclusion, for sound deductive arguments merely say the premises are true and the argument is valid. One cannot say anything more about the conclusion of a sound deductive argument other than it has true premises, and is valid. True premises only have to be true by a factor of 51%. So the idea that sound deductive arguments produce certain conclusions is hogwash!

Also hogwash is the contention that non-deductive (or inductive) arguments are weaker than deductive arguments, since both non-deductive and deductive arguments depend on premises that are probabilistic in nature.