Irrationality, not being in ratio or the quantitative relation between two amounts showing the number of times one value contains or is contained within the other (South African Concise Oxford Dictionary, 3rd impression page 970).
Constitutional Judge Zak Yacoob with unanimous concurrence of nine (9) other fellow judges at paragraph 27 of the judgement found: ‘The Minister and Mr Simelane accept that the “executive” is “constrained” by the principle that [it] may exercise no power and perform no function beyond that conferred ... by law” and that the power must not be misconstrued. It is also accepted that the decision must be rationally related to the purpose for which the power was conferred. Otherwise the exercise of the power would be arbitrary and at odds with the Constitution. I agree.’
The judgement went on from paragraph 28 to emphasise the distinction though overlapping between “reasonableness and rationality” finding at paragraph 32 of the judgment that “rationality review is really concerned with the evaluation of a relationship between means and ends: the relationship, connection or link (as it is variously referred to) between the means employed (one side – my insert) to achieve a particular purpose on the one hand and the purpose (other side – my insert) or end itself. The aim ... is only whether the means employed are rationally related to the purpose for which the power was conferred.”
This is in line with the definition of the root word ratio as setting a formula which determine basically and or mathematically a relationship between two (2) of a kind to be the same. The kind in this case being that related to a legal enquiry and the same being the provisions (jurisdictional requirements) of the law and the factual circumstances of the case before the court or legal forum. It is as simple as 2 (one side) = 1+1 (other side).
To arrive at this determination, whether the law (the specific section of an Act) is equal to the fact (circumstances of a specific case) the judgment found in paragraph 36 is not only looking at the end result but the process followed in arriving at that end result: “Not only the decision employed to achieve the purpose, but also everything done in the process of taking that decision, constitute means towards the attainment of the purpose for which the power was conferred.” This would necessary mean to say two is = to one + one. The = and + sign being essentially the process.
If one of the steps or material in the process showing equality between jurisdictional requirements and factual circumstances does not show “rational relation” the decision is irrational. The decision maker have to look at all material or facts in the process of those material or facts developing or coming into being right up to and relevant to the exact legislative provision(s) it seeks to satisfy.
In simple terms the executive must understand what is equal to what. The executive must be sane.