Fas is an indeclinable Latin neuter noun meaning "divine law" or "what is right in the eyes of the gods," most often appearing as fas est + infinitive ("it is right to..."). Its opposite, nefas, marks an act as religiously forbidden, a distinction Vergil uses constantly in the Aeneid.
Fas is the Latin word for divine law, the unwritten rules of what the gods allow. When something is fas, it's morally and religiously permitted. When something is nefas (literally "not-fas"), it's an abomination, an act that violates the cosmic order. You'll almost always see it in the construction fas est plus an infinitive, meaning "it is right to..." or "it is lawful to..."
Grammatically, fas is weird in a useful way. It's an indeclinable neuter noun, so it never changes its ending no matter what role it plays in the sentence. That's exactly the kind of grammar-meets-meaning detail the CED cares about (AP Latin 1.22.C). You can't rely on case endings to spot its function, so you have to read the context. In Vergil, fas carries serious thematic weight. Aeneas's mission to found Rome is fas because the gods sanction it. Acts driven by furor (like Turnus breaking treaties or Dido cursing her own death) drift toward nefas.
Fas lives in Topic 1.22 (Vergil Aeneid Epic Elements) and supports all three vocabulary learning objectives. You need to define it cold (AP Latin 1.22.A), recognize its sense in context (1.22.B), and explain how an indeclinable noun functions in a sentence (1.22.C, where word formation matters too, since nefas is just ne- + fas). Beyond vocabulary, fas is one of the value-words that powers analytical essays. The Aeneid's whole moral architecture runs on the line between what the gods permit and what they forbid, so when you argue about pietas, fate, or Aeneas's choices, fas is the word that names divine approval.
Keep studying AP Latin Unit 1
Furor (Unit 1)
Furor is fas's enemy in the poem. Rage and uncontrolled passion push characters across the line into nefas, while Aeneas's job is to suppress furor and act within divine law. Pair these two words and you have the Aeneid's central conflict in four syllables.
Fides (Unit 1)
Fides (good faith, loyalty) is fas applied to human relationships. Breaking an oath isn't just rude in Vergil's world, it offends the gods, which is why treaty-breaking scenes use the language of nefas.
Omen (Unit 1)
Omens are how the gods tell mortals what is fas. When Aeneas hesitates, signs like the flame over Ascanius's head or the comet in Book 2 confirm that leaving Troy is divinely sanctioned, not desertion.
Foundation legend (Unit 1)
The founding of Rome is the ultimate fas-approved act. Vergil frames Aeneas's journey as obedience to divine law, which turns a refugee story into a charter myth justifying Roman power.
Fas and nefas show up directly in exam passages. The 2022 short-answer question quoted Charon's warning from Aeneid 6, "corpora viva nefas Stygia vectare carina" (it is forbidden to carry living bodies on the Stygian boat), so you needed to recognize nefas as "forbidden/unlawful" and handle the impersonal construction with an infinitive. For translation questions, render fas est literally as "it is right/lawful" rather than paraphrasing. In multiple-choice and analytical essays, fas works as evidence. When a question asks how Vergil characterizes Aeneas or frames Troy's fall, pointing to fas/nefas vocabulary shows you can connect word choice to theme, which is exactly what high-scoring analysis does.
They look similar and both involve the gods, but they're different ideas. Fata (the fates, destiny) is what WILL happen, the fixed outcome even Jupiter respects. Fas is what is PERMITTED, the moral rules for getting there. Aeneas reaching Latium is fata; how he behaves along the way is judged by fas. Watch the grammar too. Fata declines normally (it's the plural of fatum), while fas never changes form.
Fas means divine law or what the gods permit, and it usually appears as fas est plus an infinitive, translated "it is right to..."
Fas is an indeclinable neuter noun, so it keeps the same form in every case, and you have to use context to find its function in the sentence.
Nefas is the direct opposite of fas (the prefix ne- negates it) and labels an act as religiously forbidden, like Charon refusing to ferry the living in Aeneid 6.
Don't confuse fas with fata: fata is destiny (what must happen), while fas is divine permission (what is allowed).
In the Aeneid, fas anchors the poem's moral system, marking Aeneas's mission as divinely sanctioned and acts of furor as violations of cosmic order.
Fas means "divine law" or "that which is right/permitted by the gods." It's most common in the phrase fas est + infinitive, meaning "it is right (or lawful) to do something."
No. Fata is destiny, the fixed outcome of events, while fas is divine permission, the moral standard for actions. Aeneas's arrival in Latium is decreed by fata, but whether a character's behavior is acceptable to the gods is a question of fas.
Nefas is the negative of fas (ne- + fas) and means something religiously forbidden or unspeakable. Vergil uses it in Aeneid 6 when Charon says it is nefas to carry living bodies across the Styx, a line that appeared in a 2022 AP short-answer question.
No, fas is indeclinable. It's a neuter noun that keeps the exact same form regardless of case or number, so you identify its function from word order and context, not endings.
Translate it literally as "it is right" or "it is lawful," followed by the infinitive. The exam rewards literal translation, so avoid loose paraphrases like "it's okay to" and keep the impersonal construction intact.