In "The Tai Chi Book: Refining and Enjoying a Lifetime of Practice," Robert Chuckrow, physics PhD and tai chi practitioner since 1970, has this fascinating point to make about tai chi teachers and where they might come from:
It is possible to learn from a teacher whose identity is completely unknown to the student. This may sound unbelievable, so prepare yourself for something strange. The teacher may be a consciousness that may or may not even reside in a living body. The teacher may have died and not yet have been reborn. Or, the teacher may at present be a child who, in a past life, attained some sort of mastery. It may be that the teacher had a strong connection with the student but passed on. Or, the teacher may have had no connection in this life, but, rather, in past lives. Or, the connection may even be much less fathomable. The student may not even be consciously aware of being taught through "spirit." Such an awareness, however, can make the process more efficient. If the instruction is coming, for example, through dreams (as mine most often does), the student can do various things to increase the likelihood that contact will be made and that what is received is consciously retained upon awakening. Future contacts can be initiated by consciously desiring the contact to be made. Retention can be increased by an awareness that an important process is taking place. The knowledge that you are being helped in spirit adds an extra keenness to your receptivity.~Robert Chuckrow, The Tai Chi Book, page 109
The idea that non-corporeal teachers were involved in my practice was floating around (har har) in the club I trained in long before I had any direct conscious awareness that I was personally receiving such guidance. And when that guidance manifested, it was really only as the barest of whispers.
I remember training up at my family cottage, in the part of Ontario just west of Algonquin park. I had my weapons, a water bottle, and time to spend all afternoon working out. One of my favourite things to do when I'm all on my own is to go through each of the sets I know one by one, usually in this order: tai chi, lok hup, hsing-i, sword, sabre. I was warming up and thinking about where I would start, and all of a sudden, I felt a strong impulse to pick up the sabre first.
"Practice your turning," a thought came through - by which I understood I should work on the spiral turn of the spine. Not "Hey, I should work on turning the spine," or, "It would be cool to practice turning my spine."
This was much more like a directive.
I silently thanked the source of the thought, thinking without fully believing that it didn't come from me, and I proceeded to practice.
Now, whenever I get the chance to do a lot of solo practice, I always start with the sabre.
I don't recommend relying exclusively on a non-corporeal teacher to learn tai chi. (Almost) everybody needs a physical, visceral human teacher to help connect with this practice. But I do believe that when we pick up a tai chi sword, or we start to learn tai chi stepping, or we practice any of the Taoist arts, a chorus of non-corporeal beings, from teachers who have passed out of the physical world to dragons to guardians, stands by ready to help us.