I love Nasr Hossein and Sufism. But:
Philosophy can guide you to the truth but it cannot take you there. It is a horse but at some point you must dismount.
Philosophy is like football, that’s why dogmatic Theologians hated it and they had a point: because there’s no absolute right or wrong about it, no absolute winner.
But we can say that this philosopher or that concept, consistently wins the debate. Why? The criteria to me are logical fallacies. Look to whose arguments are thick with fallacies. They are dishonest even if unknowingly. They have no counterarguments and are being (l hate this phrase, it’s for show-offs) cognitively dissonant.
There is universal truth in the Human Intellect. It is the silvering of the mirror on which the epiphany of God manifests. It manifests on the entire mirror and even the glass reflects him, but the actual silvery-type layer is the acme of it, the best of it. That’s the human intellect.
So even false religion manifests something of the truth. It doesn’t mean all religions are true-true, but they are all revealing of something or the other.
Even a drill rapper or a fat slob eating one pizza too many before his gut literally explodes, reveals something of the Epiphany.
Sufism embodies a lot of core human ideals. These can be catalogued in beautiful books, as indeed they are. There are about 100 l wanna buy.
But as Idris Shah told a budding disciple bursting into his office clutching one of his publications: Throw the book away.
So you see: Sufi philosophy won’t have every truth. And it doesn’t matter that a Primordial Tradition that maybe has every truth, has every truth. In so far as the spiritual quest is concerned, all that matters is that a person is selected.
The alternative is the way of Simon Magus, ascending up by his own power then crashing back down. This is not just a stinking wizard, it’s all of us, so long as we have the ego in charge, from football hooligans to politicians to philosophers - we all end up crashing back down to earth after a brief stint. “Die before you die” the Sufis say, kill that ego. In a roundabout way that also means “ditch your erudite ecumenical block of principles”.
Same line of thought destroys what you wrote about Spiritual Realisation and Symbolism.
Can anybody be better than my mommy? She was just a housewife and a simple woman who was a slave to her children, no Spiritual Realisation, no Primordial Tradition, no Symbolism - yet l am confident she is in heaven. I don’t care which part of heaven, any will do. Can you ask for more?