Sentence:  In order to be saved , plasticity had had to be isolated ; and as the aspect of the subject was transposed into those clusters of more or less interchangeable and contour obliterating facet-planes by which plasticity was isolated under the Cubist <WSD>method</WSD> , the subject itself became largely unrecognizable . 
Meaning of the word marked with <WSD> tags:  a way of doing something, especially a systematic way; implies an orderly logical arrangement (usually in steps)