useful latin phrases & terms

There is a really useful and comprehensive latin dictionary of international legal terms: Aaron Fellmeth & Maurice Horowitz, Guide to Latin in International Law (Oxford: Oxford University Press, 2009). WCL has the print version in our collection (K 52.L37 F45 2009). The main AU Library subscribes to Oxford Reference (with 5 concurrent users), and that database includes the online version.

de lege ferendā
of (or from) the future law, of (or from) the law that should be (the ablative case of lex ferenda)
de lege lata
of (or from) the law borne (carried), of (or from) the law that exists (the ablative case of lex lata)
lex ferenda
the future law, the law that should be (in the nominative case); in other words, aspirational law
lex lata
the law borne (carried), , the law that is, the law that exists (in the nominative case)
lex posterior derogat priori
a later law repeals an earlier law (one of the general principles regulating the relationship of norms deriving from the same source)
lex posterior generalis non derogat priori speciali
a later general law does not repeal an earlier specialized law (one of the general principles regulating the relationship of norms deriving from the same source)
lex specialis derogat generali
a specialized law prevails over a general law (one of the general principles regulating the relationship of norms deriving from the same source)
ne bis in idem
not twice for the same thing (in the imperative mood), no one should be tried twice for the same act, no double jeopardy
non bis in idem
not twice for the same thing (as a result clause), no one should be tried twice for the same act, no double jeopardy
non impediti ratione cogitationis
unencumbered by the thought process
nulla pœna sine lege
no punishment without law, no one may be punished except how it is set out in the law
nullum crimen sine lege
No crime without law, no person may be convicted for an act that was not a crime at the time of commission
proprio motu
from its own motion, the court or prosecutor deciding to do something without being prompted by another party (sometimes proprio suo motu)
ratione personæ
by reason of the person concerned; in criminal jurisdiction, the power of the court to hear a case based upon who is charged
ratione temporis
by reason of the time the act was committed; in criminal jurisdiction, the power of the court to hear a case based upon when the act was committed
ratione loci
by reason of the place concerned; in criminal jurisdiction, the power of the court to hear a case based upon where the act was committed
ratione materiæ
by reason of the subject-matter involved; in criminal jurisdiction, the power of the court to hear a case based upon whether the crime charged falls within the subject-matter jurisdiciton of the court