Plutarch Quaestiones Romanae 78

[78] Why of birds is the one called left-hand a bird of good omen?

Is this not really true, but is it the peculiarity of the language which throws many off the track? For their word for left is sinistrum; to permit is sinere: and they say sine when they urge giving permission. Accordingly the bird which permits the augural action to be taken, that is, the avis sinisteria, the vulgar are not correct in assuming to be sinistra and in calling it so.

Or is it, as Dionysius ¹ says, that when Ascanius, son of Aeneas, was drawing up his army against Mezentius, and his men were taking the auspices, a flash of lightning, which portended victory, appeared on the left, and from that time on they observe this practice in divination? Or is it true, as certain other authorities affirm, that this happened to Aeneas? As a matter of fact, the Thebans, when they had routed and overpowered their enemies on the left wing at Leuctra, ² continued thereafter to assign to the left the chief command in all battles.

Or ³ is it rather, as Juba ⁴ declares, that as anyone looks eastward, the north is on the left, and some make out the north to be the right, or upper, side of the universe?

But consider whether it be not that the left is by nature the weaker side, and they that preside over auguries try to strengthen and prop its deficient powers by this method of equalization.

Or was it that they believed earthly and mortal matters to be antithetical to things heavenly and divine, and so thought that whatever was on the left for us the gods were sending forth from the right?

[78]

Question 78.

What is the reason that a bird called sinister in soothsaying is fortunate?

Solution. What if this be not true, but the dialect deludes so many? For they render ἀριστέρον sinistrum; but to permit a thing is sinere, and they say sine when they desire a thing to be permitted; therefore a prognostic permitting an action (being sinisterium) the vulgar do understand and call amiss sinistrum. Or is it as Dionysius saith, that when Ascanius, the son of Aeneas, had pitched battle against Mezentius, a flash of lightning portending victory (as they prognosticated) came on his left hand, and for the future they observed it so; or, as some others say, that this happened to Aeneas? Moreover, the Thebans routing and conquering their enemies by the left wing of the army at Leuctra, they continued in all battles to give the left wing the pre-eminence. Or is it rather as Juba thinks, that to those that look toward the east the north is on the left hand, which verily some make the right hand and superior part of the world? Consider whether the soothsayers do not, as it were, corroborate left-hand things, as the weaker by nature, and do intimate as if they introduced a supply of that defect of power that is in them. Or is it that they think that things terrestrial and mortal stand directly over against heavenly and divine things, and do conjecture that the things which to us are on the left hand the Gods send down from their right hand?