Practical Criticism is not theory-based. It is performance-based. ... Practical Criticism relies on observation and critical judgment — learned skills ... Without a theory as a guide McLuhan was influenced by artists and poets in developing the analytical and conceptual tools he relied upon to examine media and communication. He referred to his procedure as starting with a problem and digging into the toolkit for something to open the matter up for elucidation. Chief among his tools of analysis was Practical Criticism, which he viewed as a kind of critic’s Swiss-Army Knife that worked equally incisively across all of the arts and through all areas of culture, from high-brow to low. The argument that emerges from this analysis of McLuhan’s investigative techniques is that many of the conundrums of modern media and culture are understood most effectively through research that transcends the constraints imposed by seeking to make the case for or against the truth of a particular theory. Begin with theory, you begin with the answer; begin with observation, you begin with questions.
" I don't know what is inside (the vault); maybe it's nothing.
I just sit and start to work. I grope, I listen, I test, I accept and
discard; I try out different sequences - until the tumblers fall
and the door springs open."