"Allatonceness"

As brilliant as this book is ('The Medium Is the Massage' by Marshall McLuan), the language is somewhat hard to digest. The word 'allatonceness' springs up half way through the book with no reference to its meaning. After scouring the net I have found no eveidence that this word exists in the English language. "Ours is a brand new world of allatonceness", is the context in which the word is used but still it gives no clue as to its meaning or origin. The search continues.