It is true that all men are mortal. It is also true that 2 + 3 = 5. Yet it is not “true” that all men are mortal, nor is it “true” that 2 + 3 = 5.
True means true. We learn from David Stove (and by experience) that by supplying scare-quotes “true” means “not true, but believed by so-and-so to be true”; which is to say, “true” means false, or, at best, unknown. Waving your fingers around truth is like becoming the assassin who puts his arm around his victim and calls him friend—as he knifes him in the back.
Yet scare-quotes are not the only, or even the best, way to sabotage logical expressions.
A slier method is to embed a truth conditionally. This example comes from Michael Voris (drop the S.T.B. Mikey, and learn to crack a smile!): “Jesus has risen from the dead, we Catholics believe.” (Voris recognized the mistake.)
This way of phrasing gives comfort to those who don’t want to acknowledge the truth—it is only the curious “belief” of some religious sect—while also releasing the teller from his duty of proclaiming a truth. So much less confrontational, you see.
Saying a truth conditionally is to kill with slow poison, not violence. “P is true, so-and-so believes”, “I believe P”, and “My professor said that P” no more imply P is true than does saying “P is ‘true’.” In other words, it is not an argument for P to say “I believe P”. It is the mere announcement of your mental state at some particular time. Since it is not an argument, there is nothing to refute, for there is no definitive way for me to know your mental state (no, not even with an electric phrenology device, i.e. an fMRI). And then all history suggests there is no point in arguing over somebody beliefs.
Update The main and obvious disadvantage of speaking this way is that it sets you back on your heels, puts you on the defensive immediately, when truth is always an offensive weapon.
So much for the easy stuff. Let’s now talk about scientists and academic philosophers and their love of talking about conditional truths (i.e. theories) as if conditional truths were truths Stove (from his Rationality of Induction, p. 117), where he gives us three arguments:
(a) “Hume is a father, therefore Hume is a male parent”,
(b) “All male fathers are parents & Hume is a father, therefore Hume is a male parent”,
(c) “If Hume is a male parent then Hume is a father & Hume is a father, therefore Hume is a male parent”.
The first, (a), is a valid argument, which is to say that its conclusions follows from the accepted premise. Since the conclusion of (a) follows from its premise, we can augment that premise, which is why (b) and (c) are also valid (rule of logic: “if p entails q, then p-and-r entails q, for any r“).
But (b) is an example of the formal fallacy ‘undistributed middle term,’ and (c) is an example of the formal fallacy ‘affirming the consequent’ (look them up). Even so, (b) and (c) are still valid. This means that something is wrong with the formality, i.e. the theory, which declares them invalid. Yet philosophers, like scientists, are loathe to abandon a beautiful theory. This creates a severe difficulty, and even psychic pain, for those who cherish the formality (theory):
[T]he formal logician cannot call (a), (b), or (c) valid, consistently with his professional creed: hence his disapproval of them. But he dares not call them invalid either: hence his unease.
A situation so painful as this one is bound to produce distress signals, even if only half-conscious ones. Some of the commonest of these signals sound as follows. ‘Argument (c) is invalid in propositional logic‘; (b) is not valid in predicate calculus‘; ‘(a) is neither quantificationally valid nor truth-functionally valid.’ You can easily see how suitable such phraseology is to the distressed logician’s situation. A phrase like ‘invalid in propositional logic’, for example, by including the word ‘invalid’, has the effect of setting the desired tone, the tone of disapproval; while at the same time it is admirably non-committal, because after all—as the formal logician himself will hasten to assure you—‘invalid in propositional logic’ no more entails ‘invalid’, than (say) ‘suspected murderer’ entails ‘murderer.’ [p. 122]
The gist: “Arguments are not ‘in’ predicate logic, or ‘in’ any other artefact that logicians may happen to make. Still less is their invalidity or validity ‘in’ anything at all, except the arguments themselves.”
In other words, all arguments have to be evaluated individually.