Sonnet 45

The speaker's air and fire (thought and desire) travel swiftly to the beloved as messengers of love, leaving the speaker with only earth and water, and sinking into death-like melancholy until they return.

Original
Modern
1 The other two, slight air, and purging fire,
The other two, weightless air and cleansing fire,
Refers back to Sonnet 44's four-element scheme. 'Purging' suggests fire's cleansing power; 'slight' emphasizes air's weightlessness.
2 Are both with thee, wherever I abide,
Are both with you, wherever I stay,
3 The first my thought, the other my desire,
The first is my thought, the other my longing,
4 These present-absent with swift motion slide.
These—present yet absent—glide swiftly away.
'Present-absent' captures the paradox: the speaker's thought and desire are physically absent but spiritually/emotionally present with the beloved.
5 For when these quicker elements are gone
For when these swift elements depart,
6 In tender embassy of love to thee,
On a tender mission of love to you,
'Embassy' suggests formal diplomatic mission; thought and desire are love's official representatives.
7 My life being made of four, with two alone,
My life, composed of four elements, left with only two,
8 Sinks down to death, oppressed with melancholy.
Sinks down toward death, crushed beneath melancholy.
Volta The volta shifts from the speaker's degradation (sinking to death) to the return of the swift elements, restoring 'life's composition' and reversing the melancholy.
9 Until life’s composition be recured,
Until the balance of life is restored,
'Recured' (recovered/healed) suggests sickness as the condition of separation; restoration of the absent elements = health.
10 By those swift messengers returned from thee,
By those quick messengers returning from you,
11 Who even but now come back again assured,
Who even now return again with confidence,
'Assured' carries double meaning: the messengers are confident, and they reassure the speaker.
12 Of thy fair health, recounting it to me.
About your beautiful wellness, reporting it to me.
13 This told, I joy, but then no longer glad,
Hearing this, I feel joy, but it doesn't last,
The volta's resolution is bittersweet: joy arrives but immediately gives way to new sorrow.
14 I send them back again and straight grow sad.
I send them back to you and immediately sink into sadness.
The couplet reveals the cyclical nature of absence: each reunion is temporary; the messenger must depart again, and the speaker's melancholy is renewed.
The Physiology of Longing

Sonnet 45 transforms absence into a medical condition: the speaker is literally decomposed when his airy and fiery elements depart, leaving only heavy earth and water behind. This is not metaphorical weakness but actual elemental imbalance, a kind of lovesickness that medieval medicine might recognize. The return of the messengers 'recures' (heals) him—but only temporarily, as the couplet makes clear. Love oscillates between sickness and fleeting health.

The Paradox of Messengers

The 'swift messengers' (thought and desire) are the speaker's own consciousness projected outward. They travel to the beloved and return with news—but this circuit is what drains the speaker to near-death. The very faculties that make love possible are those that leave him empty. Resolution comes only from their return, yet that return is always temporary. The speaker is trapped in a cycle of his own making: loving requires the very self-fragmentation that brings melancholy.

If this happened today

Imagine a chronic illness where your energy (air and fire, your vitality) briefly surges as you check your phone for a message from your beloved. While waiting, you feel drained, almost comatose. The moment they reply—the moment your 'messengers' return—you're alive again. Your entire being oscillates between deadness and rebirth based on contact.