Not exactly. Nocturne is unique in that regard in that, at first, you're supporting three social philosophies that only kinda sorta map to L/C and kind of an extreme Neutral, but are much more nuanced. But you can also actively reject all of them, and seek to bring about *your* philosophy (well, the Protag's philosophy, anyway), or you can also passively deny them and shirk the responsibility.
Also, none of these directly relates to the so-called "True Demon" ending, which you get if you complete the optional dungeon regardless of your choices throughout the main game (unless you're going with the passive wishy-washy option, that is). If you completed it, TD will override whichever path you went with at the very end of the game.
As to your specific question, it's just a matter of agreeing with or rejecting the three main proponents of the philosophies, and whether you show decisiveness or uncertainty when your teacher confronts you with general life questions. The only major difference is that, in other SMTs, "achieving balance" meant you got Neutral; here, you have to proactively reject everyone to forge your own path, or stumble into a stagnant balance by being indecisive.
Also, don't listen to people who say True Demon is canon. It's one of the more compelling paths, sure, and it has the most story/gameplay content, but there's nothing set in stone there.