St. Isaiah the Solitary, On Guarding the Intellect, Twenty-Seven Texts
11. The demons cunningly withdraw for a time in the hope that we will cease to guard our heart, thinking we have now attained peace; then they suddenly attack our unhappy soul and seize it like a sparrow. Gaining possession of it, they drag it down mercilessly into all kinds of sin, worse than those which we have already committed and for which we have asked forgiveness. Let us stand, therefore, with fear of God and keep guard over our heart, practising the virtues which check the wickedness of our enemies.
From the initial counsels about freeing the intellect and becoming at rest, we turn now to a crucial warning. It is tempting to think that, once freed, one has no enemies. Isn't this just what happens after great military victories? But the elation of V-E day yields shortly to the realization that the true enemies are not so quickly vanquished.
The modern tendency is then to say that the true enemies are internal, and in a sense, this is right. But the mythological language here, of demons, is helpful. Don't get caught up in metaphysics! The point is that the forces which plague us are not, truly, internal, but rather, external, and they succeed by a cooperation between the internal and external. What makes the external demons able to accomplish their nefarious task is an inward readiness for them.
And, alas, that readiness is what happens if we "cease to guard our heart, thinking we have now attained peace." It is the consequence of the spiritual pride, which would say, "I have now purified the intellect, and I am at peace," and that suddenly makes it possible for the true reality: that freedom and peace are not so simple.
It is when we think that we have nothing more to do that this warning comes to play. The spiritual pride of thinking that we have reached our goal is precisely the thing which opens us to even greater dangers.
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