"[W]hen we speak of Chan in China, we need to keep in mind that we are speaking of a thousand experiments on a thousand mountain peaks." (Mu Soeng; Trust in Mind)
Might we not similarly say that when we speak of any spiritual endeavor, we are speaking of a personal experiment? As I like to say, there are as many paths as there are pairs of feet to walk them. Even when we follow a certain traditional path, it might be better described as finding our own path up a traditional mountain.
Soeng's statement is not intended to suggest that, after much experimentation, the true way was discovered. Not at all. It is always and only this experimentation — if the individual journey is to be authentic.
He also makes the point that Gautama’s philosophical revolution was motivated in part by a rejection of the ontological substantiality, the 'ultimate' of Brahman, in the Brahmanism of his day. In other words, "he was a phenomenologist"; his interest was in the human experience, not in establishing 'facts' about ultimate Reality. Thus, by extension, does he similarly critique every other idea of the so-called Ultimate — Dao as Source, God, I Am, Universal Mind, and the rest.
This conditioned propensity to establish Being so as to secure our being easily infiltrates even those philosophies which began in the acknowledgement of no such thing; and thus did a Buddhism now religiously reifying Buddha, when it encountered the "not-knowing" of neo-Daoism, reform itself in Chan (Zen). (Neo-Daoism being a reform of religious Daoism, which had similarly lost itself in belief.) Or something like that.
What is left is upaya, "skillful means", always-provisional (and thus self-emptying) ways of understanding our being-in-the-world. As with everything else, my understanding of upaya has been rather shallow; I have thought of it as only applying to method — a fish-trap forgotten when the fish are caught. But Soeng demonstrates how upaya applies to our every understanding of and relationship with the world — the fish, too, are upaya.
And thus are the teachings of the Buddha "therapeutic rather than absolutist" and "a series of fictions" (Conze) designed to facilitate a certain favorable outcome. And thus does Zen suggest that if we meet the Buddha we had best kill him, for in meeting him we have met a lie.
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