Alexander, I realized something just now when I read this. I CAN tell who is a Noble One and who isn't. In fact, let me tell you a short and interesting story that jumps at me most prominently.
I was going to a artistic competition with my partner, because she used to love participating, but couldn't any longer. So we went to see her sister. As we were walking up to the school (which is where it was held), a very interesting african american man met with us where two paths to the school meet. Instantly, I knew him. I don't know why, but as soon as I saw him I felt "This is a brother." I've never felt that before. Never. And I had no reason to even have it in my head. I never thought about an ability to discern noble ones or anything like that.
What's crazy, is he knew it, too. He never said it, and we barely talked for a minute, but I knew it, and I knew he knew it. Our eyes met, and we both smiled the biggest smile I've ever given a "stranger." And you know how I don't normally look humans in the face because of their thoughts and mind states, so this was significant.
As soon as my partner and I were seated, I said to her "I think that man is enlightened." (This is something I've never said about someone I've met in ordinary life.) And now, I even know the ones who don't know that they are Noble (or at least a proto-mystic). I attract them to me, or I can just tell. I don't know what's going on. I just thought that I was attracting more wholesome and skillful people because I had changed my outer life to reflect my mind. But, oh god, is it really the case that the only wholesome and skillful humans are the Noble Ones?