[The_Gun_Nut]

Not "passive" as in "does nothing," more passive as in "doesn't jump around doing stuff by itself."  Belief is the touchstone of thought, it shapes and is shaped by it, but it is more a list of criteria within the mind that is used to determine choices as opposed to a thing that wanders about rearranging the furniture.

[RHat]

Belief has a profound impact on unconscious processes.  Just because you're not distinctly aware of the effect doesn't mean its not there - conscious thought is just the tip of the mental iceberg.

In any case, though, I'm talking about something well beyond the bounds of how spells are cast - what magic is, rather than simply how it is manipulated.  Are you suggesting that thought influences the shape of the metaplanes?  It seems to me that, especially with the impact of symbolism within magic, thought is an insufficient explanation.

[The_Gun_Nut]

It's not just metahuman thought that floats out there.

[RHat]

It's not just metahuman thought that floats out there.

Which doesn't change the basic facts of the question - in fact, I did not at any point limit my criticism in that manner.

[The_Gun_Nut]

It's limited in that it only applies thought that you understand (human thought).

While this is a bit artsy and dodgy, there are countless entities in the astral that often only barely notice metahumanity, if at all.  They impress their thoughts upon the space around them.  And they do not conform to any pattern metahumanity is(currently)  familiar with.  They do so in ways humans do not understand.

And, yes, thought does have an impact upon the metaplanes.  Again, it isn't just metahuman thought, although that is the kind we are most familiar with.  That symbolism that works in 2074 is not the same symbolism that existed in the 4th world.  Some of it is similar, yes, but most of it is not.  Metahuman thoughts, habits, and patterns (or expectations, that might be more accurate) are impressed upon astral space.  Repeated actions wear the energy into a pattern that can be discerned by those with the appropriate abilities.  What happened previously is different that what happens now (in the 6th world).  It is similar, but not quite the same, because metahumanity's thoughts or patterns of behavior are different.  (One could say beliefs, but as I have stated earlier, that is indirect.)

I could go on some more, but I have to get up at 430 am.  We can discuss more later, if you like.

[RHat]

I'd be quite happy to continue this later.  Though, I'm at this point trying to find a differentiating aspect to look at to make it a little easier to contrast the theories we're forwarding - I'm not sure, off hand, what sort of observable differences there would be between magic as a force of thought and magic as a force of belief (where does Resonance fit into your line of thinking, by the way?).