subtilises

This conception is latent in Malory, but it is central in Tennyson; and everywhere he subtilises, refines, elevates, and, in short, modernises the _Motivirung_ in the old story.

A History of English Romanticism in the Nineteenth Century 1886

Fragile, spiritual as is the apparition, the sunbeam refines, subtilises, spiritualises it still more.

Eleanor Humphry Ward 1885

In my country, and in my time, learning improves fortunes enough, but not minds; if it meet with those that are dull and heavy, it overcharges and suffocates them, leaving them a crude and undigested mass; if airy and fine, it purifies, clarifies, and subtilises them, even to exinanition.

The Essays of Montaigne — Volume 16 Michel de Montaigne 1562

In my country, and in my time, learning improves fortunes enough, but not minds; if it meet with those that are dull and heavy, it overcharges and suffocates them, leaving them a crude and undigested mass; if airy and fine, it purifies, clarifies, and subtilises them, even to exinanition.

The Essays of Montaigne — Complete Michel de Montaigne 1562