It is sufficient to choose any set of synonyms placing them in a simple context to demonstrate the point. Let us take, for example, the synonyms from the above table.
Cf.: He glared at her (i. e. He looked at her angrily). He gazed at her (i. e. He looked at her steadily and attentively; probably with admiration or interest).
He glanced at her (i. e. He looked at her briefly and turned away).
He peered at her (i. e. He tried to see her better, but something prevented: darkness, fog, weak eyesight).
These few simple examples are sufficient to show that each of the synonyms creates an entirely new situation which so sharply differs from the rest that any attempt at "interchanging" anything can only destroy the utterance devoiding it of any sense at all.
If you turn back to the extracts on p. 184—187, the very idea of interchangeability will appear even more incredible. Used in this way, in a related context, all these words (/ like you, but I cannot love you; the young man was strolling, and his child was trotting by his side; Romeo should smile, not grin, etc.) clearly demonstrate that substitution of one word for another is impossible: it is not simply the context that firmly binds them in their proper places, but the peculiar individual connotative structure of each individual word.
Consequently, it is difficult to accept interchange-ability as a criterion of synonymy because the specific characteristic of synonyms, and the one justifying their very existence, is that they are not, cannot and should not be interchangeable, in which case they would simply become useless ballast in the vocabulary.