Some men are so guileless that they do not recognize what righteousness is. But the more they forsake the innocence of true simplicity, the more they fall to rise to moral rectitude; for in not knowing how to guide their actions by right living, they are too simple to remain innocent. Hence Paul warns his disciples, saying: I want you to be wise in what is good but guileless in evil. And again, do not be like boys in your thinking, but be like infants in evil. Thus the Truth himself bids his disciples: Be wise as serpents and simple as doves. In this command he has deliberately joined the two ideas together; the serpent’s cunning complements the dove’s simplicity, and the dove’s simplicity moderates the serpent’s cunning. This is why the Holy Spirit reveals his presence to men not only as a dove but also as fire. For the dove symbolizes simplicity, and the fire, intense dedication. Thus the dove and the fire, taken together, have a special significance: whoever is filled with the Spirit becomes so dedicated to this gentle simplicity that he is also aflame with the zeal of righteousness against the faults of sinners.