I finished up Leithart’s From Silence to Song yesterday and found his writing illuminating as always. He discusses the Reformed “Regulative Principle” and recasts it in a very different light (a much better one). The Regulative Principle is usually held to mean that anything God hasn’t expressly commanded in worship is forbidden, you’ll often see it trumpeted in modern times by nuts like the Still Waters Revival folks who hold to no instruments in music and exclusive Psalmody.
Leithart contrasts this with the canonical example of David’s instructions for Temple and Tabernacle worship. He writes:
A strict regulativist living at the time of David would syllogize thus:
Major premise: Whatever is not commanded is forbidden.
Minor premise: Singing is not commanded in the Levitical Law.
Conclusion: Therefore, singing in worship is forbidden.
David appears to have reasoned by analogy:
Major premise: The Law governs worship.
Minor premise #1: The Law prescribes that trumpets be played over the public ascensions, in public worship.
Minor premise #2: The trumpet is a musical instrument.
Conclusion: Analogously, song and other music are a legitimate part of worship.
In place of a “regulation-by-explicit command” principle, David operated according to a “regulation-by-analogy” principle.
He qualifies this by showing that not all analogies are valid – pigs can’t be offered in sacrifice because cows are, so Scripture controls the application. Once again, Leithart’s writings are some of the best theological insights you can find today on a host of subjects.