承認量能原則得以審查稅法，稅法之思維風格已轉為憲法思維風格，而為稅法之革命。我國自納保法施行以來，有賴部分行政法院判決逐步糾正稽徵機關人員之傳統思維模式，惟其仍囿於行政法思維模式。唯究竟稅法有無獨立於民法、刑法、行政法之獨特方法論，本文試從三個角度切入，一般法學方法到稅法學方法論、平等原則到量能原則、干預行政法到協同行政法三個稅法特色與法學方法，並以最高行政法院108年度大字第3號裁定為分析。該號裁定所論及之盈虧互抵，乃為量能原則之客觀淨所得展現，雖立法者對其互抵之年限具有裁量權，但仍不得逾越憲法界線，此種朝向憲法思維模式之轉換，顯示納稅者權利法護法第1條第1項，即合憲解釋、合憲補充與違憲審查乃稅法方法論之特色。

The recognition of ability-to-pay principle as reviewing standard of tax law implies the revolutionary change of a constitutionalized mindset in tax law. The traditional collection-oriented mindset came to be rectified by numeral case law of administrative courts after enforcement of Taxpayers Right Protection Act but restrained itself in the administrative-law thinking, left to be constitutionalized. The further question of whether tax law has its proper methodology independent from civil, criminal, and administrative law remains. This paper attempts to look into it from three perspectives, i.e., the developments from general legal methodology to methodology of tax jurisprudence, from principle of equality to ability-to-pay principle, and from the infringing-characterc of administrative law to cooperative administrative law, with a focus on the Supreme Administrative Court Ruling D. T. No.3 in 2019. The said ruling involves the offset between profits and losses, symbolic of the requirement of objective net-income in ability-to-pay principle. Despite legislative discretion on the offsetting period, such legislation is subject to constitutional review. The shift to a constitutional mindset indicates that Sec 1, Art. 1 of the Taxpayers Right Protection Act, namely to constitutionally interpret, supplement as well as to review, justify itself as methodology of tax jurisprudence proper.