of the sorrow makes it for the time seem like a vast physical presence. When we try to attend to a difficult internal task, we meet feelings of resistance which are known to be in large part muscular feelings (derived from knit brow, clenched jaws, altered breathing), but these give us no sense that the mental object which stubbornly resists our effort to conquer it through our attention, is an external fact. The inner life is moreover full of permanent possibilities of experience which we still regard, despite their regularity of recurrence, as internal. Sleepiness normally recurs as regularly, as vividly, as intrusively, as irresistibly as the darkness of night. We, however, regard sleepiness as an internal, the darkness as an external fact, because all normal observers can verify darkness together, while as to sleepiness they do not all agree. When one man says "It is night," all his fellows assent. But when one man says "I am sleepy," either it may be daytime, or his fellows may be in full train for a night of watching, of toil, or of revel. In the simpler days of earlier civilization, when sleepiness was nearly as common to all normal observers as was the darkness of night, there was less difference in seeming between the objectivity of the two. In the Homeric poems, sleep conquers all men, and night comes down. Both are nature-powers, both relatively external facts. But, in the Homeric poems, individual insomnia is not a very common phenomenon, although Odysseus can voluntarily remain awake while the drunken Cyclops sleeps. Yet still for simple men, as for children, sleep is a more recognizably common, and therefore a more easily objectified, experience than for us, who regard the time of sleepiness as a relatively capricious individual phenomenon, dependent on personal calling, habit, whim, or state of health.
Thus, then, I insist, neither vividness, nor intrusive resistance to our will, nor peculiarly insistent relation to our muscular experiences, nor regular recurrence, suffice to define the notes of externality as we now are aware of them. It is social community that is the true differentia of our external world.
