From Coventry Kersey Dighton Patmore’s 1895 book The Rod, the Root, and the Flower:
Plato’s cave of shadows is the most profound and simple statement of the relation of the natural to the spiritual life ever made. Men stand with their backs to the Sun, and they take the shadows cast by it upon the walls of their cavern for realities. The shadows, even, of heavenly realities are so alluring as to provoke ardent desires, but they cannot satisfy us. They mock us with unattainable good, and our natural and legitimate passions and instincts, in the absence of their true and substantial satisfactions, break forth into frantic disorders. If we want fruition we must turn our back to the shadows, and gaze on their realities in God.
It may be added that, when we have done this, and are weary of the splendors and felicities of immediate reality, we may turn again, from time to time, to the shadows, which, having thus become intelligible, and being attributed by us to their true origin, are immeasurably more satisfying than they were before, and may be delighted in without blame. This is the ‘evening joy,’ the joy of contemplating God in His creatures, of which the theologians write; and this purified and intelligible joy in the shadows–which has now obtained a core of substance–is not only the hundredfold ‘promise of this life also,’ but it is, as the Church teaches, a large part of the joy of the blest….See Also
“‘Detachment’ consists, not in casting aside all natural loves and goods, but in the possession of a love and a good so great that all others, though they may and do acquire increase through the presence of the greater love and good, which explains and justifies them, seem nothing in comparison.”