Before that, no such theory existed.
The commission attempted to answer, specifically, every such theory and rumor".
One such theory is metaphysical (or "external") realism, as characterized (but not professed) by Putnam.
He was skeptical that any such theory could be plausible, and anyway his brilliance was fundamentally destructive.
One such theory is that the plane's systems were tampered with so that it only appeared to be going south.
No such theory is well enough understood to calculate the ratios of these contributions, though they are in principle determined.
Gill is making the profound point that his distrust of most such theory is not from ignorance, but from understanding.
Like any conspiracy theory, it contains several grains of truth; and like any such theory, it is both irrational and insidious.
But no such theory has yet won universal acceptance, and it is likely that the causes of sound change are multiple.
But that does not mean that every such theory is correct.Had it been shorter and better focused, Mr Wolfram's book would have been more convincing.
The most ambitious such "theory of everything," which portrays particles as strings wriggling in 10-dimensional space-time, seems to preserve the matter-antimatter symmetry, but theorists do not really understand why.
