Why do we assume? Zen and Solipsism?

From Wikipedia:

Solipsism from Latinsolus, meaning 'alone', and ipse, meaning 'self') is the philosophical idea that only one's own mind is sure to exist. As an epistemological position, solipsism holds that knowledge of anything outside one's own mind is unsure; the external world and other minds cannot be known and might not exist outside the mind. As a metaphysical position, solipsism goes further to the conclusion that the world and other minds do not exist. This extreme position is claimed to be irrefutable, as the solipsist believes themself to be the only true authority, all others being creations of their own mind.

Recently, it seems to me, that Zen is the practice of Solipsism, or at least very close to that. Open a Zen book and you'll see Zen Masters talking about these things; such as how nothing exists outside of Mind, and that all is One Mind, etc.

As to being the one true authority, Some Zen Masters like Joshu seem to suggest that one should be the king of their domain. I believe it was Mazu said “make yourself master everywhere, and wherever you stand is the true place."

One argument against Solipsism, according to Wikipedia, is:

If the external world were merely a construct of a single consciousness, i.e. the self, it could then follow that the external world should be somehow directly manipulable by that consciousness, and if it is not, then solipsism is false.

But isn't this what Zen Masters claim to be able to do? Joshu said "I can make one blade of grass be a sixteen-foot golden Buddha, and I can make a sixteen-foot golden Buddha be one blade of grass."

Finally, I'd like to ask you some things.

Why do we act with the assumption that everyone/everything does or does not exist, when we can't know for sure? Why do we pick and choose what exists and what doesn't? Why does it have to be one or the other? Does the meaning of Zen boil down to "Be a good person, because things sort of exist, but don't worry so much because things sort of don't exist."? If things other than the Mind may or may not exist, why should we have to do anything at all?

Submitted February 08, 2019 at 09:52AM by McNubbitz http://bit.ly/2SzpJ5B