Preserving the separation of powers remains crucial to statutory interpretation . The Irish courts have been conscious of the need to clearly define and delimit their role in interpreting legislation, so as to avoid any implication that they are creating law and thereby usurping the role of the Oireachtas. The role of the courts is seen as best delimited by accepting the primacy of the text of the statute as enacted by the Oireachtas - by adopting a literal interpretation. The literal rule, in its purest form, has an inflexibility which places particular strain on the draftsperson, requiring language which expressly covers all eventualities. This extreme inflexibility can be seen in the words of Lord Esher MR in R v The Judge of the City of London Court where he stated that:
"[i]f the words of an Act are clear, you must follow them, even though they lead to manifest absurdity. The Court has nothing to do with the question whether the Legislature has committed an absurdity."
The literal approach is impractical and unhelpful to the drafter, in that it fails to acknowledge the limited capacity of language, even where there is no particular ambiguity, to assert a single indisputable meaning. Neither does it acknowledge the impossibility of the drafter's taking account of every possible factual situation which may arise under a statute , and catering expressly for each of these situations in a single statutory provision. If the drafter is to write comprehensively enough to anticipate the effect of literal interpretation, it is more than likely that clarity and brevity will be sacrificed.
In the Report of the English and Scottish Law Commissions on the Interpretation of Statutes , it was commented that:
"[t]o place undue emphasis on the literal meaning of the words of a provision is to assume an unattainable perfection in draftsmanship; it presupposes that the draftsmen can always choose words to describe the situations intended to be covered by the provision which will leave no room for a divergence of opinion as to their meaning."
It is now generally recognised that the literal approach must be tempered by at least some flexibility in order to avoid an application of a statutory provision by a court which would be absurd or unreasonable. In the case of McGrath v McDermott Finlay CJ set out a modified literal approach in relatively flexible terms when he said:
"The function of the courts in interpreting a statute of the Oireachtas is ... strictly confined to ascertaining the true meaning of each statutory provision, resorting in cases of doubt or ambiguity to a consideration of the purpose and intention of the legislature to be inferred from other provisions of the statute involved, or even of other statutes expressed to be construed with it. The courts have not got a function to add to or delete from express statutory provisions so as to achieve objectives which to the courts appear desirable."
The literal approach to interpretation is stated, also in flexible form, by Budd J in Rahill v Brady :
"in the absence of some special technical or acquired meaning the language of a statute should be construed according to its ordinary meaning and in accordance with the rules of grammar. While the literal construction generally has prima facie preference, there is also a further rule that in seeking the true construction of a section of an Act the whole Act must be looked at in order to see what the objects and intention of the legislature were; but the ordinary meaning of words should not be departed from unless adequate grounds can be found in the context in which the words are used to indicate that a literal interpretation would not give the real intention of the legislature."
Thus, for example, where there is ambiguity in the terms of a provision, the long title to the Act may be used to assist in the construction of the provision.