Perusperiaatteella

Perusperiaatteella is a Finnish expression used in public administration and legal contexts to indicate that a decision, interpretation, or action is guided by a fundamental principle rather than applied by a narrowly tailored rule in every case. The phrase signals that the outcome should reflect core values embedded in the constitutional and legal order, such as equality, proportionality, and respect for basic rights.

The term is not a formal doctrine or codified principle in itself. Instead, it functions as a linguistic tool in legislation, administrative guidance, and jurisprudence to justify or frame decisions so that they harmonize with overarching principles governing the legal system. It is commonly invoked when applying ambiguous or general rules, when striving for consistency across cases, or when individual circumstances require balancing competing interests.

Typical contexts include judicial interpretation of laws with broad wording, administrative decisions that affect rights or material interests, and policy work aimed at ensuring non-discrimination and fairness. In these cases, authorities may state that effects are determined per perusperiaatteella, i.e., in line with fundamental principles, even if the statutory text does not specify the exact outcome for each situation.

Etymology: "perus-" from perusta (base), "periaate" principle, and the adverbial ending "-ella" indicating manner or basis. The phrase roughly corresponds to “on the basis of basic principles” in English.

See also: general principles of law, proportionality, equality before the law, Finnish administrative law, perusperiaate.