De Somniis (lib. i-ii)

And thanks be to God who giveth the victory and who renders the labours of the man who is a slave to his passions, though ever so carefully carried out, still unproductive and useless, sending down winged natures in an invisible manner for their destruction and overthrow. Therefore, the mind, being deprived of those things which it had made for itself, having, as it were, its neck cut through, will be found headless and lifeless, and like those who are fixed to a cross, nailed as it were to the tree of hopeless and helpless ignorance.

For as long as none of these things come upon one which arrive suddenly and unexpectedly, then those acts which are directed to the enjoyment of pleasure appear to be successful; but when such evils descend upon them unexpectedly, they are overthrown, and their maker is destroyed with them.