say that the development of Singapore public law is not accomplished in a cloister sealed off from transnational models, but through a thoughtful engagement with foreign cases." A purposive approach to statutory interpretation was mandated in Singapore in 1993 by the enactment of section 9A of the Interpretation Act, which requires a court to prefer an interpretation that would "promote the purpose or object underlying the written law (whether that purpose or object is expressly stated in the written law or not) ... to an interpretation that would not promote that purpose or object". The Constitution of the Republic of Singapore Tribunal affirmed in Constitutional Reference No. 1 of 1995 that the approach applies to constitutional interpretation as well. It stated: "It is well established ... that a purposive interpretation should be adopted in interpreting the Constitution to give effect to the intent and will of Parliament". The generous approach to constitutional interpretation mentioned in Ong Ah Chuan might be said to accord with the purposive approach because the use of broad and general language in Articles of the Constitution dealing with fundamental liberties suggests a parliamentary intention to give courts the discretion "to interpret the Constitution based on prevailing social conditions". It may also be noted that although the court may depart from previously held constitutional interpretations, it cannot disregard the text entirely. Fundamental constitutional principles The courts have been willing to uphold the spirit of the Constitution by recognizing fundamental constitutional principles not expressly mentioned in the written Constitution which underlie the Constitution and form the theoretical basis of constitutionalism, its goal being to achieve limited government. Examples of these principles include accommodative secularism, the rule of law, and the separation of powers. Similarly, the court's power of judicial review is not expressly mentioned, but has been read into the Constitution by necessary implication from Article 4 of the Constitution. Additionally, the courts have read into the Constitution extratextual principles which either have the effect of expanding or limiting the ambits of fundamental liberties. In Ong Ah Chuan, the Privy Council held that references to the word law in clauses such as Article 9(1) and Article 12(1) of the Constitution include "fundamental rules of natural justice", which were later held by the Court of Appeal to be procedural rather than substantive in nature. On the other hand, the courts have said that freedom of speech must be balanced