The aims of these three groups are entirely irreconcilable. The aim of the High is to remain where they are. The aim of the Middle is to change places with the High. The aim of the Low, when they have an aim — for it is an abiding characteristic of the Low that they are too much crushed by drudgery to be more than intermittently conscious of anything outside their daily lives — is to abolish all distinctions and create a society in which all men shall be equal.
My question is that I don't understand the meaning of the sentence in which to be more than is used.