53.3 Regulae, Ouvres, xi.
Spinoza abounds in the same sense, and is as usual perfectly candid " Naturae leges et regulae, secundum quas omnia fiunt et ex unis formis in alias mutantur, sunt ubique et semper eadem."
His ascetic tendencies are exhibited in the Moralia and Regulae, ethical manuals for use in the world and the cloister respectively.
The most important of Guido's treatises, and those which are generally acknowledged to be authentic, are Micrologus Guidonis de disciplina artis musicae, dedicated to Bishop Theodald of Arezzo, and comprising a complete theory of music, in 20 chapters; Musicae Guidonis regulae rhythmicae in antiphonarii sui prologum prolatae, written in trochaic decasyllabics of anything but classical structure; Aliae Guidonis regulae de ignoto cantu, identidem in antiphonarii sui prologum prolatae; and the Epistola Guidonis Michaeli monacho de ignoto cantu, already referred to.
He endeavoured to reconcile the Protestant churches with the Roman Catholic, and at a conference at Hanover in 1683 presented his Regulae circa Christianorum omnium ecclesiasticum reunionem.
- Epistolarum libri xiv., Moralium libri xxxv., Regulae pastoralis liber, Dialogorum libri iv., Homiliarum Ezechielem prophetam libri ii., Homiliarum in Evangelia libri These are all printed in Migne's Patrologia Latina.
The celebrated Regulae of Descartes are precepts directed to the achievement of the new methodological ideal in any and every subject matter, however reluctant.