We all have touchstones. We may not know it; we may not acknowledge the fact, we may refuse to admit little truths. But what is a real touch stone. It is a dark stone such as slate on which a precious metal leaves a trace. So a touchstone is something that lets us know the worth of something else.
I’m trying to remember whether I’ve ever seen an eastern reference to touch stone. My mind comes up rather blank. To think some people spend their lives trying to make their minds blank. OK that’s today’s giggle.
That's the surface of my thinking.