Ictus, Caesura & Diaeresis
Once you've scanned a hexameter into six feet, three more terms tell you how it actually moves. The ictus is the rhythmic beat that lands on the long syllable opening each foot — it's the BEAT you'd tap with your finger.
A caesura is a word-end falling inside a foot; the main one in a Vergilian line is a real pause where the line breathes.
A diaeresis is the opposite: a word-end coinciding with a foot-end, lining the verbal joint up with the metrical one.
The trap: the ictus and the natural Latin word-accent often disagree. Conticuēre omnēs — accent on -tī- and -nē-, ictus on con- and -ē. They CLASH for most of a hexameter and only resolve in the last two feet.
That tension is the music, not a bug. Read the line as a chant where the foot-beat wins, and let the words ride on top.
Six ictuses per line; one main caesura inside foot 3 or 4; diaeresis only when word-end and foot-end coincide.
Ictus and natural word-accent CLASH for most of a Latin line — that tension is the music. Let the foot-beat win.
See It In Action
— Verg. Aen. ii. 1
Textbook penthemimeral caesura: the word-break after omnēs falls just past the first long of foot 3. Aeneas pauses; the whole banquet leans in. Sense and meter coincide.
— Verg. Aen. i. 33
The line's emotional weight sits on the caesura: the proem closes with erat ‖, then the infinitive condere gentem delivers the punchline. Caesura and meaning are doing the same work.
— Verg. Aen. v. 277
A double-caesura line: trihemimeral after ferōx + hephthemimeral after oculīs. The third-foot break is weak, so Vergil cuts the line into three beats instead of two — three short bursts to mime the snake's flicker.
— Verg. Aen. vi. 131
The caesura in potuē-‖re falls after the second syllable of foot 3, not the first — that's a feminine caesura. The Sibyl's voice softens over the break; only certain heroes have made the journey she's about to describe.
The natural Latin word-accent (the prose stress on each word) and the metrical ictus (the foot's beat) usually DISAGREE in the middle of a hexameter. That clash IS the music.
The prose stress: penultimate if long, else antepenult.
con-ti-CU-e-re OM-nēs
natural prose stress on -CU- and -OM-
The beat on each foot's heavy first syllable.
CON-ti-cu | Ē-re-OM | NĒS...
ictus on CON-, Ē-, NĒS — clashing with the word-accent
Tip: Don't try to make them agree. Tap the ictus with your finger; let the words sing against the beat. Notice how the clash relaxes in feet 5 and 6 — the line resolves into harmony at the close. That's how Vergil ends every hexameter.
In Conticuēre omnēs ‖ intentīque ora tenēbant (Verg. Aen. ii.1), where does the principal caesura fall, and what is it called?
Study Tips
- •Find the main caesura first — usually after the third-foot first long (penthemimeral). It's where the line breathes; the rest of the rhythm clicks once you mark it.
- •Tap the ictus with your finger as you read aloud: six taps per line, one per foot, on each foot's heavy syllable. The Latin words will pull against your taps — let them.
- •If the third-foot word-break feels weak, scan ahead: the caesura may be hephthemimeral (after the fourth-foot first long), often paired with a trihemimeral break in foot 2.
- •Diaeresis is the absence of a caesura — the word and foot end together. The famous case is the bucolic diaeresis (word-end after foot 4), which gives a pastoral lilt.