Claims made from the past. What do we do with them in light of what we know today? What happens when they don't fall within our current understanding?
For instance: What do we do with the assertion made in Vocal Wisdom that the tone must start in the center of the head, especially when it is known that the vocal tract is the only resonator?
I can think of several possible scenarios. One modern response is that since the vocal tract is the only resonator, anything that is perceived in the head is not "source" material and is therefore suspect, ephemeral and should be ignored.
Another response is that whatever is uttered by revered vocal pedagogues of the past must be accepted without question. Get it in the head, baby! Doesn't matter what you do, just get it there!
Both views miss the mark in my estimation.
Accepting information without question isn't very smart. In fact, it's rather stupid. That's the blind leading the blind, and befits the acolyte who worships the self-appointed priest, one who often brooks no opposition. However, discounting historic teachings out of hand because they don't fit current understanding isn't helpful either, if only because that too stops inquiry. In both cases, one remains at a surface level of experience and understanding.
To go deep, you have to dig. And that is hard to do when you see what you are looking at through a particular lens, worldview, or set of facts. To change how you see or how you think, there has be a paradigm shift. This involves incorporating new information.
I gave a workshop recently where the example in question was explored in a practical and systematic manner, and while I didn't for one second suggest that participants send tone into their heads (that would be stupid), they experienced what is talked about in Vocal Wisdom. That and more.
How was this made possible?
I gave them exercises which opened their ears! Their minds followed in due course.