在上一篇貼文裏提到：大法官是釋憲機關，而不是制憲機關。誠如美國聯邦最高法院首席大法官 John Roberts 在 Obergefell v . Hodges 一案的反對意見書裏所指明的：「 聯邦最高法院不是立法機構。不管承認同性婚姻的合法性是否為好的政策，都不在本院的職權範圍內。在憲法的授權下，大法官有權力解釋法律是什麼，但沒有權力決定法律應該是如何。」 (But this court is not a legislature. Whether same-sex marriage is a good idea should be of no concern of us. Under the Constitution, judges have power to say what the law is, not what it should be.)

在此前提下，大法官必須謹守解釋的份際。那麼， 首席大法官 John Roberts 認為，依文義解釋的結果，美國憲法所稱「婚姻」，究應如何解釋呢？

首先，首席大法官 John Roberts 指出：「 憲法本身並未就婚姻予以定義及說明。 ….. 沒有爭議的，在各州創建之初，直至十數年前為止，均是依傳統、生物學的角度定義婚姻。 」 (The Constitution itself says nothing about marriage…. There is no dispute that every State at the founding – and every State throughout our history until a dozen years ago – defined marriage in the traditional, biologically rooted way.)

雖然憲法未就「婚姻」二字作出定義，但仍有許多文獻就「婚姻」加以解釋。舉例來說， 第一本英文字典 Noah Webster 裏即寫道：「婚姻乃是一名男性與一名女性的法律結合關係，其目的在於防止淫亂的性關係、 ….. 促進社會和樂，保護及教養子女。」 (“the legal union of a man and a woman for life,“ which served the purposes of “preventing the promiscuous intercourse of the sexes, ….. promoting domestic felicity, and ….. securing the maintenance and education of children.”) 法律人必備及必讀的 Black’s Law Dictionary ，則就婚姻有如下的定義：「一名男性與一名女性依照法律所成立的市民結合體。」 (the civil status of one man and one woman united in law for life)

這樣的歷史背景及淵源，不只一次的出現在判決先例中。誠如美國聯邦最高法院過去在 United States vs. Windsor 一案中表示：「直至近幾年為止， …… 毫無疑問的，絕大多數的人均認同，自有人類文明以來，婚姻的意義、角色、功能，均是僅存在於一名男性與一名女性之間。」 (until recent years, ….. marriage between a man and a woman no doubt had been thought of by most people as essential to the very definition of that term and to its role and function throughout the history of civilization.)

首席大法官 John Roberts 進一步說明：「 這個普世認同的定義，其來有自。它不是由政治運動、發現、疾病、戰爭、宗教定義或者其它外力因素而來的，當然更不是因為史前人類決定排除同性戀者。它是從自然的定律所產生並且符合一個重要的需求，那就是：確保孩子們是由母親與父親所生，並且父母彼此承諾在長期且穩定的關係裏，共同孕育並扶養其成人。」 (This universal definition of marriage as the union of a man and a woman is no historical coincidence. Marriage did not come about as a result of a political movement, discovery, disease, war, religious doctrine, or any other moving force of world history – and certainly not as a result of prehistoric decision to exclude gays and lesbians. It arose in the nature of things to meet a vital need: ensuring that children are conceived by a mother and father committed to raising them in the stable conditions of a lifelong relationship.)