[hosh]

Alchemy as a pseudo-chemistry is a conventional, but superficial interpretation of it. The pseudo-chemistry narrative fits well with our current, normative narratives and so we don't really question it. However the alchemists were philosophers. The Philosopher's Stone is the embodiment of the Philosophy, and as such, the Philosopher is the Philosopher's Stone in it's final stage. Or put it in different terms, the Truth extracted from philosophical investigation is then used to transmute the philosopher until there is no distinction between the philosopher and Truth. It's this last stage that, I think, many modern students of philosophy fail to take their philosophy to. You might be able to google it under "philosophical alchemy".

There are strains of alchemy that does concern itself with elixirs and transmutations of substances, but a discussion of that requires gnosis. (These strains, though, are interesting in that they are wildly proliferated in both Eastern and Western cultures).

Math is not as fundamental as people like to think it is :-D

As for non-dual Shiava Tantra, I can see why you would think it is a set of principles derived from religion. The View derives from empirical methods, reproducible, if not objective. (There is no such thing as a privileged objective view in a non-dual philosophy). Those truths form the a priori in which the rest of the View descends from. It happens to appear to be religious, but it is not religious that most people think it is. Christopher Wallis's book, Tantra Illuminated has several chapters on just the philosophical view, including how Indian philosophers have different ideas on what constitutes validity and proof. There is a section there where Wallis speaks about the non-dual Tantric View in terms of Western Philosophy.

I get that your view of philosophy has a heavy Western bias. It's for that reason that the authors of the original article is trying to champion greater diversity. Check out Wallis's book sometime, maybe just the chapters on the View.