Sentence:  Now, assuming "ideas of matter" to mean some knowledge of matter, and the " inversion of the outgo" to mean the <WSD>ingo</WSD>, which seems rational, and "creative activities" to mean that impulse in matter to evolute as we see it in the cosmos, while the only verbalism we can think of for non-being is nowhere ; then making these substitutions in his formula, and it affords a theorem something like this ; that knowledge of matter is "achieved " by the <WSD>ingo</WSD> of the evolutionary change into nowhere. 
Meaning of the word marked with <WSD> tags:  The act or process of going in.