How can you tell if somebody’s sad? *Whether (Infinite Jest)

‘How can you tell if somebody’s sad?’A quick smile. ‘You mean whether someone’s sad.’

A smile back, but still earnest: ‘That improves it a lot. Whether someone’s sad, how can you tell so you’re sure?’

Her teeth are not discolored; she gets them cleaned at the dentist all the time for the smoking, a habit she despises. Hal inherited the dental problems from Himself; Himself had horrible dental problems; half his teeth were bridges.

‘You’re not exactly insensitive when it comes to people, Love-o,’ she says.

‘What if you, like, only suspect somebody’s sad. How do you reinforce the suspicion?’

‘Confirm the suspicion?’

‘In your mind.’ Some of the prints in the deep shag he can see are shoes, and some are different, almost like knuckles. His lordotic posture makes him acute and observant about things like carpet-prints.”

“How would I, for my part, confirm a suspicion of sadness in someone, you mean?’

‘Yes. Good. All right.’

‘Well, the person in question may cry, sob, weep, or, in certain cultures, wail, keen, or rend his or her garments.’

Mario nods encouragingly, so the headgear clanks a little. ‘But say in a case where they don’t weep or rend. But you still have a suspicion which they’re sad.’

She uses a hand to rotate the pen in her mouth like a fine cigar. ‘He or she might alternatively sigh, mope, frown, smile halfheartedly, appear downcast, slump, look at the floor more than is appropriate.”

“But what if they don’t?’

‘Well, he or she may act out by seeming distracted, losing enthusiasm for previous interests. The person may present with what appears to be laziness, lethargy, fatigue, sluggishness, a certain passive reluctance to engage you. Torpor.’

‘What else?’

‘They may seem unusually subdued, quiet, literally “low.” 

—From David Foster Wallace’s novel Infinite Jest.