Mike,
My understanding of scientism as defined in Wiki is that .... Scientism is the notion that natural science comprises the most authoritative worldview or form of human knowledge, and that it is superior to all other interpretations of life.
I personally from my own subjective experiences find that notion is illusory but see no purpose in arguing against it. For as Ramana Maharshi said in his 40 verus on reality verse 3 ' The world is real.' 'No, it, is a mere illusory appearance.' 'The world is conscious.' 'No.' 'The world is happiness.' 'No.' What use is it to argue thus? That State is agreeable to all, wherein, having given up the objective outlook, one knows one's Self and loses all notions either of unity or duality, of oneself and the ego.
In the Invocatory it asks and states....
If Reality did not exist, could there be any knowledge of existence? Free from all thoughts, Reality abides in the Heart, the Source of all thoughts. It is, therefore, called the Heart. How then is one to contemplate it? To be as it is in the Heart, is Its contemplation.
I do not see where either side of the issue can be proved or disproved by concepts and reasoning alone but i do believe that the state Ramana speaks of is agreeable to all.
Joseph