In vino veritas is a Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 phrase that translates, “in wine [there is the] truth". It is also known as a Greek phrase “Ἐν οἴνῳ ἀλήθεια” En oino álétheia, which has the same meaning. The author of the Latin phrase is Pliny the Elder

Pliny the Elder

Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

; the Greek phrase is attributed to the Greek poet Alcaeus.

The Greek poet Alcaeus

Alcaeus (poet)

Alcaeus of Mytilene , Ancient Greek lyric poet who supposedly invented the Alcaic verse. He was included in the canonical list of nine lyric poets by the scholars of Hellenistic Alexandria. He was an older contemporary and an alleged lover of Sappho, with whom he may have exchanged poems...

 is the oldest known source for the phrase. The Roman historian Tacitus

Tacitus

Publius Cornelius Tacitus was a senator and a historian of the Roman Empire. The surviving portions of his two major works—the Annals and the Histories—examine the reigns of the Roman Emperors Tiberius, Claudius, Nero and those who reigned in the Year of the Four Emperors...

 described how the Germanic peoples

Germanic peoples

The Germanic peoples are an Indo-European ethno-linguistic group of Northern European origin, identified by their use of the Indo-European Germanic languages which diversified out of Proto-Germanic during the Pre-Roman Iron Age.Originating about 1800 BCE from the Corded Ware Culture on the North...

 always drank wine while holding councils, as they believed nobody could lie effectively when drunk.

The phrase is often continued as, "In vino veritas, in aqua sanitas", i.e., "In wine there is truth, in water there is health."

Similar phrases exist across cultures and languages. In Chinese, there is the saying, "酒後吐真言" ("After wine blurts truthful speech"). The Babylon

Babylon

Babylon was an Akkadian city-state of ancient Mesopotamia, the remains of which are found in present-day Al Hillah, Babil Province, Iraq, about 85 kilometers south of Baghdad...

ian Talmud

Talmud

The Talmud is a central text of mainstream Judaism. It takes the form of a record of rabbinic discussions pertaining to Jewish law, ethics, philosophy, customs and history....

 (תלמוד בבלי) contains the passage: "נכנס יין יצא סוד", i.e., "In came wine, out went a secret".

It continues, "בשלשה דברים אדם ניכר בכוסו ובכיסו ובכעסו", i.e., "In three things is a man revealed: in his wine goblet, in his purse, and in his wrath." (In the original Aramaic, the words for "his goblet", "his purse", and "his wrath" rhyme and are a play on words all using the root "כס".)

In the 1770s, Benjamin Cooke wrote a glee

Glee (music)

A glee is an English type of part song spanning the late baroque, classical and early romantic periods. It is usually scored for at least three voices, and generally intended to be sung unaccompanied. Glees often consist of a number of short, musically contrasted movements and their texts can be...

by the title of In Vino Veritas. His lyrics [with modern punctuation, etc.] are as follows:

Round, round with the glass, boys, as fast as you can,

Since he who don't drink cannot be a true man.

For if truth is in wine, then 'tis all but a whim

To think a man's true when the wine's not in him.

Drink, drink, then, and hold it a maxim divine

That there's virtue in truth, and there's truth in good wine!