There is a sense in which all Christians have always practiced "discernment".
That is, Christians could only seldom - and never continuously - live in complete and perfect obedience to The Church (whatever that church might be). Because the situations of life are specific, while rules are general; and because there was always a degree (sometimes a very large degree) of disunity (or at least ambiguity) among the statements and instructions of church authorities.
So people might not know exactly what to do, and would need to make up their own minds; or people would have to decide who to obey when contradictory instructions were given - and so forth.
But this kind of discernment acknowledged that ultimately - legitimate authority lay externally from each Man - in the church - mediated by the church, not the individual person; and that therefore discernment was being used to discover the true nature of that authority.
The core purpose of ancient unity was a life of obedience.
This ancient kind of discernment was essentially passive and partly unconscious - indeed, it had something of the quality of an 'unfortunate necessity'. Ideally, as little discernment as possible would be necessary in life - because church guidance was clear and unified, and people would be naturally obedient.
And when life did not change much from one generation to another: such an ideal could be approached closely.
Indeed, the ideal of ancient discernment was to forget itself, and to assume that the Christian life was a life of simple obedience to the church; unchanging and clear guidance for in navigating-through the recurrent, repeating, problems of human life.
At all costs, awareness of the discernment of individual persons was not supposed to extend to a sense of active responsibility for one's salvation and conducting life. The desired discernment was externally-directed, towards discovering the true-source of guidance within the church - and was not striving to be self-aware.
The consciousnesses of modern Men are differently constituted; and this affects both laymen and priests, those within and outside the churches: all churches.
Overwhelmingly; Modern Man experiences himself (whether he likes it or not) as starting from the situation of being cut-off from the institutions of his society. His condition is one of alienation.
He no longer takes institutions for granted, can no longer un-consciously follow their guidance, can no longer actually-be passive and obedient merely.
This alienation, cut-offness, is now simply taken for granted as the basis of our society, in multiple forms of discourse. It does not need arguing - it is just assumed as a situation, as a problem.
Life is experienced as choices; and these choices impinge on consciousness - we choose and are aware that we choose.
Such awareness permeates modern discourse - it is the subject matter of the vast bulk of modern stories and narratives - such that we simply take it for granted. Yet to experience life as multiple choices is recent, modern; and was not an aspect of ancient human life (except maybe for a very few exceptional individuals).
What this modern consciousness means is that the ancient discernment is not possible.
I would also argue that ancient discernment is not desirable either; that ancient discernment is now "not a good thing" - but the fact of its impossibility is one reason why striving for it is not desirable.
But what we have nowadays instead of ancient discernment is self-blinding and dishonesty. In other words people who claim to be anciently-discerning are actually obscuring their own acts of conscious discernment (perhaps by not-thinking, by distraction, by projection...) - or else they know they are consciously discerning but lie about the fact - maybe for exploitative, maybe for manipulative reasons.
At the very least; ancient discernment is nowadays something chosen, rather than something spontaneous; it is something we are aware or doing (or, more often, as aspiring to do) rather than something so natural that it Just Happens.
What Romantic Christianity does is to recognize the change in consciousness; and to assume (from an understanding of world history, and the nature of the divine plan) that this change was of-God.
In other words; modern man's consciousness is different because (and in so far as) God wants it that way - for our own good, for the good of our actual, specific souls; as these were incarnated into this mortal life.
God wants for us to make conscious choices, and to know we are doing so: and to take responsibility for doing so!
God does not want for us not-to-think, to distract or suppress awareness; to pretend that 'nothing has happened' and that the religious life Now is the same as for a Catholic peasant in the Christian-permeated (no-alternatives) societies of the Middle Ages.
God does not want us to be dishonest with ourselves or with others - even (especially!) when this dishonesty is self-justified as a "necessary lie" for the public good... Does not want that we try and pretend that our Christian life can be, or is; one of 'simple obedience' to a church whose ultimate goodness and authority should simply be taken for granted.
Surely? God wants for us to be honest: therefore wants us to be honest about our situation - and honest that it is what it is.
Nowadays discernment is far more necessary, more frequent; and far more conscious - than ever in the past; and this Just Has overturned the earlier ideal of the Christian life as being one of passive, unconscious, self-forgetful obedience to an external institution - A Church.
We now actually-have (like it or not) an active role in chiseling-out our own path through life. We are aware of being personally responsible for many discernments about which we could, in the past, have been unconscious.
Our situation is what it is, our discernment ought to be active, we should take full responsibility for the necessary and frequent choices of Christian living, and we should strive-for, and explicitly acknowledge, the fullest-possible consciousness of all this!
That is perhaps one fundamental assumption of "Romantic Christianity": deliberately taking conscious and personal responsibility for that which - in the past - were often matters of obedience to an external (ideal) institution.