The Supreme Court, in the case of Reynolds v. U. S. (1878), adopted, or at least cited with approval, the definition of the word "religion" used by James Madison's in his famous Memorial and Remonstrance of 1785 when it wrote,
The Reynolds Court apparently subscribed to the Rules of Constitutional Interpretation promulgated by Justice Joseph Story in 1833 , in Chapter 5 of Book 2 of his "Commentaries on the Constitution", which advise that:
§ 397. IN our future commentaries upon the constitution we shall treat it, then, as it is denominated in the instrument itself, as a CONSTITUTION of government, ordained and established by the people of the United States for themselves and their posterity. 1 They have declared it the supreme law of the land. They have made it a limited government. They have defined its authority. They have restrained it to the exercise of certain powers, and reserved all others to the states or to the people. It is a popular government. Those who administer it are responsible to the people. It is as popular, and Just as much emanating from the people, as the state governments. It is created for one purpose; the state governments for another. It may be altered, and amended, and abolished at the will of the people. In short, it was made by the people, made for the people, and is responsible to the people. 2
§ 398. In this view of the matter, let us now proceed to consider the rules, by which it ought to be interpreted; for, if these rules are correctly laid down, it will save us from many embarrassments in examining and defining its powers. Much of the difficulty, which has arisen in all the public discussions on this subject, has had its origin in the want of some uniform rules of interpretation, expressly or tacitly agreed on by the disputants. Very different doctrines on this point have been adopted by different commentators; and not unfrequently very different language held by the same parties at different periods. In short, the rules of interpretation have often been shifted to suit the emergency; and the passions and prejudices of the day, or the favour and odium of a particular measure, have not unfrequently furnished a mode of argument, which would, on the one hand, leave the constitution crippled and inanimate, or, on other hand, give it an extent and elasticity, subversive of all rational boundaries.
§ 399. Let us, then, endeavour to ascertain, what are the true rules of interpretation applicable to the constitution; so that we may have some fixed standard, by which to measure its powers, and limit its prohibitions, and guard its obligations, and enforce its securities of our rights and liberties.
§ 400. I. The first and fundamental rule in the interpretation of all instruments is, to construe them according to the sense of the terms, and the intention of the parties. Mr. Justice Blackstone has remarked, that the intention of a law is to be gathered from the words, the context, the subject-matter, the effects and consequence, or the reason and spirit of the law. 3 He goes on to justify the remark by stating, that words are generally to be understood in their usual and most known signification, not so much regarding the propriety of grammar, as their general and popular use; that if words happen to be dubious, their meaning may be established by the context, or by comparing them with other words and sentences in the same instrument; that illustrations may be further derived from the subject-matter, with reference to which the expressions are used; that the effect and consequence of a particular construction is to be examined, because, if a literal meaning would involve a manifest absurdity, it ought not to be adopted; and that the reason and spirit of the law, or the causes, which led to its enactment, are often the best exponents of the words, and limit their application. 4
§ 401. Where the words are plain and clear, and the sense distinct and perfect arising on them, there is generally no necessity to have recourse to other means of interpretation. It is only, when there is some ambiguity or doubt arising from other sources, that interpretation has its proper office. There may be obscurity, as to the meaning, from the doubtful character of the words used, from other clauses in the same instrument, or from an incongruity or repugnancy between the words, and the apparent intention derived from the whole structure of the instrument, or its avowed object. In all such cases interpretation becomes indispensable.
The best "subject-matter", with reference to which the word "religion" was used, and explicitly defined, was, according to the Reynolds Court, James Madison's famous Memorial and Remonstrance of 1785. There were other writings on the subject of religious liberty, prior to the framing of the First Amendment, that also used the word "religion" and explicitly defined it as Mr. Madison did in his Memorial and Remonstrance of 1785.