Fundamental Rights and Justice

1. Audi alteram partem The principle that no person should be judged without a fair hearing. It requires that both sides must be heard before passing any order. This principle is fundamental to natural justice and forms the basis of fair judicial proceedings.
2. Nemo judex in causa sua No one should be a judge in their own cause. This principle prevents bias and ensures impartial justice. It’s a fundamental principle of natural justice that requires judges to recuse themselves from cases where they have a personal interest.
3. Actus curiae neminem gravabit An act of the court shall prejudice no one. This principle ensures that parties should not suffer due to court delays or errors.

Criminal Law Principles

1. Actus non facit reum nisi mens sit rea The act alone doesn’t make a person guilty unless there’s a guilty mind. This forms the basis of criminal liability requiring both actus reus (guilty act) and mens rea (guilty mind).
2. Nulla poena sine lege There can be no punishment without law. This principle ensures that no person can be punished for an act that wasn’t prohibited by law when committed.
3. De minimis non curat lex The law does not concern itself with trifles. Courts generally don’t deal with insignificant matters or technical violations that cause no substantial harm.

Civil Law and Contracts

1. Qui facit per alium facit per se He who acts through another acts himself. This principle forms the basis of the law of agency and vicarious liability.
2. Caveat emptor Let the buyer beware. This principle places the onus on buyers to examine goods before purchase, though modern consumer law has modified its application.
3. Volenti non fit injuria No injury is done to a willing person. This principle bars recovery when a person has knowingly and willingly placed themselves in a dangerous situation.

Property Law Principles

1. Cuius est solum, eius est usque ad coelum et ad inferos Whoever owns the soil owns everything up to the sky and down to the depths. This principle defines the extent of land ownership, though modern laws have modified its application.
2. Quic quid plantatur solo, solo cedit Whatever is affixed to the soil belongs to the soil. This principle relates to fixtures and improvements made to land.

Administrative Law

1. Delegatus non potest delegare A delegate cannot delegate further. This principle limits the power of administrative authorities to sub-delegate their powers unless expressly permitted.
2. Ultra vires Beyond the powers. Actions of administrative authorities beyond their legal powers are void.

Evidence and Procedure

1. Res ipsa loquitur The thing speaks for itself. In certain cases, the very nature of an accident implies negligence.
2. Falsus in uno, falsus in omnibus False in one thing, false in everything. This principle suggests that a witness who lies about one matter may be unreliable in all matters.
3. Onus probandi Burden of proof lies on the person who asserts, not on the person who denies.

Constitutional Principles

1. Stare decisis To stand by decisions. This principle of precedent ensures consistency in judicial decisions and forms the basis of common law.
2. Doctrine of Eclipse Laws inconsistent with fundamental rights remain inoperative until the inconsistency is removed.
3. Doctrine of Severability If part of a law is unconstitutional, only that part is void, not the entire law, unless the parts are inseparable.

Special Maxims for Interpretation

1. Expressio unius est exclusio alterius Express mention of one thing excludes others. This principle is used in statutory interpretation.
2. Ejusdem generis Of the same kind or nature. When specific words are followed by general words, the general words are limited to things of the same kind.
3. Generalia specialibus non derogant General provisions do not derogate from special provisions. This principle helps resolve conflicts between general and specific laws.

Important Modern Legal Principles

1. Rule of Law All persons and authorities are subject to law. This principle ensures equality before law and absence of arbitrary power.
2. Principle of Proportionality Administrative action should be proportionate to the objective sought to be achieved.
3. Doctrine of Legitimate Expectation Protection of reasonable expectations created by administrative authorities through their conduct or promises.