Logic and linguistic [language] are useful tool for understanding and communicating elements of reality, but they have limitations which we must be very mindful of.
The Limitation of Logic
There are loads of writing on the limitation of logic.
Here's Kant point re the limitations of logic which give logic its advantages;
In abstracting, logic only deal with the bare forms or concepts of an object rather than the real object concerned.Kant in CPR wrote:The sphere of Logic is quite precisely delimited; its sole concern is to give an exhaustive exposition and a strict proof of the Formal Rules of all Thought, whether it be a priori or Empirical, whatever be its Origin or its Object, and whatever hindrances, accidental or natural, it may encounter in our Minds.
That Logic should have been thus successful is an advantage which it owes entirely to its Limitations,
whereby it is justified in abstracting indeed, it is under obligation to do so from all Objects of Knowledge and their differences, leaving the Understanding nothing to deal with save itself and its Form.
This is why logic has a problem when dealing with more objects and things at higher precisions and in complex modes.
This is especially so when dealing with "humans" which are 'infinitely' complex - the human brain has 100 billion neurons each with up to 10,000 synapses [connectors]. [note this point!]
The Limitation of Language [linguistics].
There are loads of writings re the limitation of language and linguistics.
Here is a quick reference from wiki;
- Problems in the philosophy of language
4.1 Formal versus informal approaches
4.2 Problem of universals and composition
4.3 Nature of language
4.4 Translation and interpretation
— Ludwig Wittgenstein
The point is with the limitations inherent in logic and language, both the logic FSK and linguistic FSK do not represent reality precisely but rather crudely.
Relatively the mode and FSK that is more precise in representing reality than the logical and linguistic FSK is the Scientific FSK which is the most credible we have at present.
Thus we can use the scientific FSK as the standard bearer of the truths of reality with the other FSKs having lower degrees of credibility.Kant in CPR wrote:Logic, therefore, as a propaedeutic, forms, as it were, only the vestibule of the sciences; and when we are concerned with specific Modes of Knowledge, while Logic is indeed presupposed in any critical estimate of them, yet for the actual acquiring of them [knowledge] we have to look to the sciences properly so called, that is, to the Objective Sciences.
However, note, despite the scientific FSK is the standard bearer of the truths of reality, scientific truths are at best mere 'polished conjectures' [hypothesis] and not the ultimate objective truth of reality.
Facts and truths are specific to a Framework and System of Knowledge [FSK].
As such moral facts and truths are specific to a Moral FSK.
I argue the Moral FSK is similar to the scientific FSK.
Thus if the scientific FSK credibility rating of reality is 99/100,, then the moral FSK will have a credibility rating of 80/100.
Meanwhile I will rate the logic FSK at 49/100 given that logic is dealing with the bare forms [universals] of reality and the linguistic FSK at 55/100.
As Kant had stated to be more precise with reality, logic will have to fall back on the scientific FSK.
Given that moral-fact-deniers [e.g. PH et. al] rely on the logic and linguistic FSKs with credibility rating of logic at 49/100 and linguistic at 55/100, their views has no credibility on the moral facts justified and verified empirically and philosophically from within a moral FSK at a rating of 80/100.