On the basis of the inability of the usual methods to inhibit it

Hello,

Could anyone paraphrase the words in red, blue?

1. Does "on the basis of inability of the usual methods to inhibit it" modify "a reflex" or "solve the problem of ... on the basis of..."?

I guess "on the basis of ..." modifies "to solve the problem", because there's a word-methods.

2. What are the meanings of the red, blue parts?

Here's my try: (I think the following interpretation is wrong, especially the words underlined.)

It is impossible to solve the problem of the inborn character which is caused by conditioned reflex, via usual methods to inhibit that doesn't work?

Thanks!

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(from Conditioned Reflex Therapy)

Pavlov spoke of an inborn reflex of freedom and an inborn reflex of slavery.' Bechterev criticized this.' ". . it is not possible to solve the problem of the innate character of a reflex merely on the basis of the inability of the usual methods to inhibit it, [which was Pavlov's criterion] but it is necessary to turn in this case to an examination of the problem of its origin, for, only when we state the fact that the given reaction has originated independently of the animal's life conditions and of the external activities which have influenced it, have we the right to regard it as an innate reflex."