Nathanael Culverwell, a English scholar of the law, wrote a book on the Natural Law entitled An Elegant and Learned Discourse of the Light of Nature. In the fourth chapter of that work, he discusses the nature of law. Culverwell expresses some dissatisfaction with St. Thomas Aquinas's definition of law in his Summa Theologica, Ia–IIae, Q. 90, art. 1 as Lex est quaedam regula & mensura, secundum quam inducitur aliquis ad agendum, vel ab agendo retrahitur (law is a certain rule and measure, according to which any agent is led to act, or restrained from acting). His complaint is that it is too restrictive. During his critique of the scholastic theologian, Culverwell, like a bird taking off in sudden flight, turns toward Plato. Spreading his poetic wings, Culverwell, relying on Plato, decides to liken law to music and pens these wondrous words:(from An Elegant and Learned Discourse of the Light of Nature, ed. Robert A. Greene and Hugh MacCallum, (Indianapolis: Liberty Fund, 2001) (spelling modernized).)
A Law is such a just and regular tuning of Actions, as that by virtue of this they may conspire into a moral music, and become very pleasant and harmonious. Thus Plato speaks much of that Εὐρυθμία&συμφωνία [melody and harmony] that is in Law, and in his second book De Leg.7 he does altogether discourse of harmony, and does infinitely prefer mental and intellectual music, those powerful and practical strains of goodness, that spring from a well-composed spirit, before those delicious blandishments, those soft, transient touches that comply with sense, and salute it in a more flattering manner; and he tells you of a spiritual dancing that is answerable to so sweet a music, to these τὰθείοτατααὐλήματα [most divine flutings]. While the Laws play in consort, there is a Chorus of well ordered affections that are raised and elevated by them.
And thus as Aristotle well observes, some Laws were wont to be put in verse, and to be sung like so many pleasant odes, that might even charm the people into obedience.
’Tis true, that learned Philosopher gives this reason of it, they were put into verse, ὅπωςμὴἐπιλάθωνται, that they might remember them the better: but why may not this reason also share with it, that they might come with a greater grace and allurement, that they might hear them as pleasantly as they would do the voice of a Vial or an Harp, that has Rhetoric enough to still and quiet the evil spirit?