irrationalis

Forms

irratiōnālis (neuter irratiōnāle); third-declension two-termination adjective^[1]

Etymology

It is from Latin in- (“not”) + ratiōnālis (“rational, of reason”).^[2][1][3] De Vaan derives ratiō (“calculation, account, reason”) from the participle of reor (“to think, reckon”), whose original sense he takes to be “to count”; he traces the verb to Proto-Italic *rē- and Proto-Indo-European *Hreh₁-.^[4]

Earliest recorded meaning

Köbler records it first in Celsus.^[3] In the 1st century AD Seneca and Quintilian use it of a creature without reason, animal irratiōnāle.^[5][6]

Semantic evolution

Lewis & Short mark it as post-Augustan.^[5] It describes beings without the power of reason, above all animals,^[5][6] and Quintilian also uses it of a practice done mechanically, without method, for which he gives a Greek equivalent.^[2][6] He also uses the neuter plural irratiōnālia as a noun, “creatures without reason”.^[5] The grammarians Diomedes and Martianus Capella set it against ratiōnālis.^[6] In Christian Latin Tertullian speaks of an anima irratiōnālis and has the adverb irratiōnāliter, “irrationally”.^[5] In medieval British Latin it is used of souls, animals and the world, of faculties or acts without a rational foundation, and in mathematics of an irrational line, also called surda.^[7]

Timeline

• 14–37 AD – First recorded, in Celsus.^[3]
• 4 BC–65 AD – Seneca, in his letters, of animals without reason.^[5][3]
• c. 35–95/96 AD – Quintilian, of animals and of mechanical practice.^[2][5][3]
• c. 160–220 AD – Tertullian, of the soul, and the adverb irratiōnāliter.^[5][3]

Meanings

Adjective

1. Without reason, irrational, unreasoning (of animals and other beings).^[2][5][6]
2. Done without method, mechanical (of practice or exercise).^[2][5][6]
3. (as a noun, neuter plural) Creatures or things without reason.^[5]
4. (Medieval Latin) Lacking a rational basis, unreasonable.^[7]
5. (Medieval Latin, mathematics) Irrational, surd (of a line or quantity).^[7]

Related words

• irratiōnābilis
• ratiōnālis
• ratiō
• English irrational

Usage notes

The OLD treats it as the same word as irratiōnābilis, “unreasoning, irrational”;^[2] spellings with inr- occur in manuscripts.^[5][8]

References

1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
3. ^ a b c d e f Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
4. ^ de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
5. ^ a b c d e f g h i j k l Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
6. ^ a b c d e f Georges, Karl Ernst (1913–1918), Ausführliches lateinisch-deutsches Handwörterbuch, 8th ed., ed. Heinrich Georges, Hannover; Leipzig: Hahn
7. ^ a b c Latham, R. E., D. R. Howlett, R. K. Ashdowne, et al. (1975–2013), Dictionary of Medieval Latin from British Sources, London: British Academy / Oxford University Press
8. ^ Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften