Messiaen on freedom

Came across in a CD sleeve note Messiaen's manifesto that was supposedly being circulated by the composer himself before performances of his early organ piece La Nativité du Seigneur. One statement stands out for me:

"And the abundance of technical means allows the heart to overflow freely."

I am immediately reminded of the American composer Roger Sessions's admonition that

"If the composer is to avoid becoming—and remaining, at least to some degree—the slave of his own technical limitations, he has to learn to overcome them; and he can do this most efficiently by beginning at the beginning."

The obvious point above is of course the importance of grounding in compositional fundamentals, but perhaps less obviously (and back to Messiaen's quote) it also suggests to me that analysis is about identifying the technical means that the composer has made use of in the piece concerned and seeing how these technicalities are turning into expressive results.