. Cunningham - Repetti, supra note 218, with 27; See also Brian J. Arnold, Reflections on the Relationship Statutory Between Interpretation and Tax Avoidance, 49 Canadian Tax J. 1, 2, 13-19 (2001) (suggesting that a leeral approach to Canadian courts led the Supreme Court of Canada to "stop several blatant tax evasion systems"). Although the Ramsay case of 1982 seemed to indicate the development of an anti-abuse judicial doctrine in the United Kingdom, it did not bear fruit. Judith Freedman, Interpreting Tax Statutes: Tax Avoidance and the Intention of Parliament, 123 Law Q. Rev. 53, 58 (2007); See also Roy Rohatgi, Basic International Taxation 31 (2002) (describes the national approach to legal interpretation as literal in many countries). It is possible to argue, however, that the regulation of the section, which is to pay particular attention to extrinsic sources in the interpretation of tax treaties, could effectively undermine tax abuse, since these sources may include textual legal advice. However, such courts, which stick to textualist precedents, would most likely be hostile to my approach anyway. I therefore do not think that the prescribed methodology would exacerbate the problem if it does not lead to the dissemination of textualism to other interpretive bodies. Since I recommend the inclusion of a large number of extrinsic sources, the chances of such an interpreter, who focuses exclusively on a textualist source, are slim.
If so, my prescribed methodology should encourage courts and other institutions to consider extrinsic sources on the basis of international norms or laws, to reconsider their textualist tendencies.  Note that my analysis is limited to dual income agreements and not to other types of tax agreements and agreements, such as inheritance tax and donation agreements or tax information exchange agreements. Nor does my analysis apply to contracts that have tax consequences or contain isolated tax provisions. I limit my thesis to the judicial elements of the double taxation conventions, which are the backbone of the treaty, and not to those aspects that have essential operational implications - in particular non-discrimination, the exchange of information and the provisions relating to mutual agreements. While I focus on American sources and jurisprudence, my general conclusion - that the liberal use of extrinsic sources in the interpretation of tax treaties is appropriate - applies to other legal cultures. Article 31 of the Vienna Convention provides that a contract is interpreted "in accordance with the ordinary meaning that contractual terms are to be given in context and according to its purpose and purpose." 82 "Purpose" is not the subjective intent of the parties, but rather the objective of the contract.83 "Context" may be excavated by a logical agreement of the contracting parties in relation to the contract. Article 31 also provides that the interpreter must take into account subsequent agreements of the parties, subsequent practices that highlight the parties` agreement on interpretive issues and all relevant rules of international law.