Robert Alexander Stewart Macalister,
Ecclesiastical Vestments: Their development and history
“ The chasuble surmounts and safeguards all the other vestments; hence the chasuble signifies love, which surmounts all the other virtues, and safeguards and illumines their beauty with its protection; so says Rabanus Maurus, prettily enough. Amalarius disagrees; he holds that as the chasuble is common to all clerics, so it ought to set forth the works which are common to all: fasting, thirsting, watching, poverty, reading, singing, praying, and the rest. The pseudo-Alcuin and Ivo of Chartres agree with Rabanus, though for different reasons. ”
