Duhaime's Law Dictionary

Quam legem exteri nobis posuere, eandem illis ponemus Definition:

Latin: What law is imposed by foreign powers on our merchants, we will impose on their's.
William Blackstone suggests, at Book 1, page 260 of his Commentaries on the Laws of England (1756), that this historic principle of international trade or, as it was then know, law merchant, is a reflection of a policy of the Swedes.

His precise translation:

"We will impose the same law on foreign merchants that they have imposed on us."

Thomas Tayler renders the maxim as:

"The same law which foreign powers have shown us, we should observe to them."

While the Latin maxim itself is not in the Magna Carta, the principle is espoused by the 1215 document. In the Magna Cartamerchants are promised safe conduct into, through and out of England except that in time of war, their persons and property is seized until such time as the government ascertains the treatment being afforded English merchants within or by the enemy state(s). The actual text of the relevant section of the Magna Carta:

"All merchants may enter or leave England unharmed and without fear, and may stay or travel within it, by land or water, for purposes of trade, free from all illegal exactions, in accordance with ancient and lawful customs. This, however, does not apply in time of war to merchants from a country that is at war with us. Any such merchants found in our country at the outbreak of war shall be detained without injury to their persons or property, until we or our chief justice have discovered how our own merchants are being treated in the country at war with us. If our own merchants are safe they shall be safe too."


  • Tayler, Thomas, The Law Glossary (London: Lewis & Blood, 1856)

Categories & Topics:

Always looking up definitions? Save time with our search provider (modern browsers only)

If you find an error or omission in Duhaime's Law Dictionary, or if you have suggestion for a legal term, we'd love to hear from you!