Scientism — epistemological & metaphysical ...

Historically, scientism has been a qualitiless epistemology—that is, scientismists limited human knowledge to quantity. Thus Nietzsche (from the notebooks):

'Our "knowing" restricts itself to ascertaining quantities ...' (5.36) 'Everything for which the word "knowledge" makes any sense refers to the realm where there can be counting, weighing, measuring, refers to quantity ...' (6.14)

And thus Russell (and the positivists generally):

'Physics is mathematical, not because we know so much about the physical world, but because we know so little: it is only its mathematical properties that we can discover ...' (An Outline of Philosophy, 171)

'The physical world is only known as regards certain abstract features of its spacetime structure ...' (Human Knowledge, 240)

Now, such epistemological scientism leads directly to a scepticism vis–à–vis metaphysics. For science works with ultrararefied mathematical abstracta. Going back to Russell:

'It is not always realised how exceedingly abstract is the information that theoretical physics has to give ... All that physics gives us is certain equations giving abstract properties of their changes. But as to what it is that changes, and what it changes from and to—as to this, physics is silent ...' (My Philosophical Development, 13)

Yes, as to whatness, as to quiddity, we are very much in the dark—if we're scientismists. (Truly, then, scientismists as such never know what they're talking about.) But, then, why be scientismists? After all, there isn't even a logically-valid way to affirm scientism, as such affirmations are extrascientific. For example, the proposition 'The only knowable propositions are scientific' isn't scientific (∴ isn't knowable). What about comparatives? You might think that the dictates of mathematics are surer than those of other dictators. You might say: 'I may be most sure of mathematics.' But, again, this proposition isn't itself among the most-sure assurances of mathematics. Compare the Reformation slogan: sola scriptura. The problem here is that the scriptures themselves do not say sola scriptura, that the slogan is itself extrascriptural. So if it's true, it's false. Similarly, scientism's dicta are extrascientific. And if they're true, they too are false.

Nowadays, however, scientism is also a qualitiless metaphysic—that is, scientismists now limit not just what may be known to quantity, but also what may exist. See, all those ultrararefied abstracta somehow became submundane concreta.

The new scientism has no masterly philosopher-generals in its army. (Surprise, surprise.) Its soldiery is mostly of scientists and journalists—some of whom are very sharp qua scientists and journalists. Problem: scientism is a philosophy, the battlefield, the weaponry, are philosophical. (Too bad for scientism!)