All law must comply with the overriding principle of reasonableness, which comprehends rationality, proportionality, and effectiveness.
All law must have a demonstrably legitimate purpose. That means that law must have a purpose which commends itself to the mind of the reasonable person. If the law does not have that effect or, in the worst case, appears to have a purpose that is perverse, then it is not legitimate. Law whose purpose is obscure or appears capricious likewise fails the test of reasonableness.
ELEMENTS OF THE IMPERATIVE
Rationality – This is the requirement that the law must be reasonably related to a legitimate governmental purpose. Legitimate government purposes are those purposes that are expected to be accomplished by the anticipated objectives of the proposed legislation. The objective of legislation must always be the advancement of the common interest.
Proportionality – This is the requirement that the proposed legislation does not cause a greater harm than that which it is intended to address.
Effectiveness – Laws should be reasonably capable of achieving the ends they are apparently intended to achieve.
Core – Sections 32, 33, 34 of the Constitution.
Supporting – Section 195 of the Constitution.