to such persons I shall make it appear that, as the mother-of-pearl oyster lives in the sea without taking in a drop of salt-water; and as, near the Chelidonian islands, springs of fresh water may be found in the midst of the sea; and as the firefly moves through the flames without singeing its wings; even so, a vigorous and resolute soul may live in the world without being infected by any of its contaminations, may discover sweet springs of piety amidst its bitter waters, and may fly through the flames of earthly concupiscences without burning the wings of the holy desires of a devout life. This, it is true, is a difficult task, and therefore I could wish that many would endeavour to accomplish it with more ardour than has been hitherto used; and I, weak as I am, shall endeavour by this treatise to contribute some kind of help to those who, with a generous heart, undertake so worthy an enterprise.
Yet it was neither by my own choice nor inclination that this Introduction now appears in public. A truly honourable and virtuous soul, having some time since received of God the grace of aspiring to a devout life, desired my particular assistance for that purpose; and I, being in many ways obliged to her, and having long before dis-
