40 Legal Maxims every Lawyer must be aware of

1.     ab initio-from the beginning. 

2.     actus reus- Part of what proves criminal liability. You must have heard of Mens rea already which means the intention behind doing something. Actus reus deals with the ‘act’ itself.

3.     ad hominem-Attacking an opponent's character rather than answering his argument. Not allowed in Court. 

4.     affidavit-Oh we all know this one!

5.     animus possidendi – It means intention to possess.  In order to claim possessory rights, an individual must establish physical control of the res and the intention to possess. Mostly used while dealing with Transfer of Property Act.

6.     bona fide-Means in good faith. I thought this was English for a very long time. 

7.     Caveat- Basically means a warning. Used in clauses. I recall the erstwhile editor of The Statesman, C.R. Irani used to write a weekly column by the same name. 

8.     sine qua non – Means an indispensable and essential action, condition, or ingredient. My Copyright professor used it very often, now I use it often too.

9.     de jure- Cousin brother of de facto, it means something that is established in law, whether or not it is true in general practice Concerning the law. 

10. de minimis–  See de minimis rule of Copyright. Enuf Said!

11. dictum-  A statement given some weight or consideration due to the respect given the person making it. Statements by Learned Hand, Justice Frankfurter, Anton Scalia , I am just throwing names.

12. ejusdem generis-It is one the aids to interpretation of Statutes. It states that when a limited list of specific things also includes a more general class, that the scope of that more general class shall be limited to other items more like the specific items in the list.  For example, where "cars, motor bikes, motor powered vehicles" are mentioned, the word "vehicles" would be interpreted in a limited sense (therefore vehicles cannot be interpreted as including airplanes).

13. ex parte-  A decision reached, or case brought, by or for one party without the other party being present. 

14. habeas corpus-It’s a writ under Article 226 of the Constitution of India by which the High Courts are given power issue certain writs. Habeas corpus is one of them. It is used to challenge the legality of detention. Orders the detaining party to "have the (living) body" of the detained brought before the court where the detention will be investigated. 

15. ibid. – Essential for writing legal research papers. We use it to increase the number of citations. Kidding. 

16. in curia-  In court

17. in loco parentis– Means In the place of a parent, basically a guardian.

18. in pari materia-In the same matter

19.  in re- Means in the matter . The name of cases begin with In Re at times. 

20.  in toto- Just mentioned cause my constitutional law professor used it 
frequently to describe things like, we were absent from the class in toto. 

21. ipso facto-Means by the fact itself. Use of this will earn you brownie points in case of an argument. 

22. jus cogens-One of the principles of International Law. Refers to laws that bear no deviation, and do not require treaties to be in effect. An example is law prohibiting genocides and crimes against humanity.

23.  lacunae-Oh well, everyone has those!

24. lis pendens-Suit pending

25. locus standi– Basically determines why a particular person is coming to court to seek relief. What is his interest?

26.  male fide- Those intentions!

27.  modus operandi– You already know this one. 

28. mutatis mutandis In simple words,  having been changed that which needed to be changed.  A caution to a reader when using one example to illustrate a related but slightly different situation. The caution is that the reader must adapt the example to change what is needed for it to apply to the new situation.

29. non liquet-  It is not clear  type of verdict where positive guilt or innocence cannot be determined. Also called "not proven" in legal systems with such verdicts.

30. noscitur a sociis-  Also a statute of interpretation. An ambiguous word or term can be clarified by considering the whole context in which it is used, without having to define the term itself. When a word is ambiguous, its meaning may be determined by reference to the rest of the statute.

31.  obiter dictum-Not the judgment but the observations made by the court. Sometimes more important than the ratio decidendi. See No. 36. 

32. pacta sunt servanda – Also part of International Law . Basically means agreements must be kept

33. per curiam-A decision delivered by a multi-judge panel, such as an appellate court, in which the decision is said to be authored by the court itself, instead of situations where those individual judges supporting the decision are named.

34.  pro bono-  You’ve seen way too many episodes of Boston Legal already. Need I explain it? 

35.  quo warranto-Also a writ under Article 226 of the Constitution. The meaning of the term Quo Warranto is ‘by what authority’. The writ of quo warranto may be issued against a person holding a public office or governmental privilege. The issue of summon is followed by legal proceedings, during which an individual's right to hold an office or governmental privilege is challenged.

36. ratio decidendi The point in a legal proceeding, or the legal precedent so involved, which led to the final decision being what it was.

37. res judicata- A matter that has been finally adjudicated, meaning no further appeals or legal actions by the involved parties is now possible. Section 11 of the Civil Procedure Code. 

38.  sui generis-When a special and unique interpretation of a case or authority is found to be necessary. When citing cases and other authorities, lawyers and judges may refer to "a sui generis case", or "a sui generis authority", meaning it is a special one confined to its own facts, and therefore may not be of broader application. 

39.  supra-Also used to increase the number of citations in a legal research paper like Ibid. 

40. Audi Alteram Partem - Hear both the parties.