The second thing from which the understanding must be guarded is curiosity; for by filling it with hurtful, vain, and impertinent thoughts we incapacitate and disable it from apprehending that which most nearly affects our true mortification and perfection.
To this end, you must be as one dead to all needless investigation of even lawful earthly things.
Always restrain your intellect as much as possible, and love to keep it low.
Let the news and the changes of the world, whether great or small, be to you as though, they were not; and should they intrude themselves, reject and drive them from you.
Be sober and humble even in the desire to understand heavenly things, wishing to know nothing but Christ crucified, His life, His death, and what He requires of thee. Cast all other things far from you, and so shall you be very pleasing unto God. For He loves and delights in those who desire and seek of Him such things alone as serve to the love of His divine goodness and the fulfillment of His will. All other petitions and inquiries belong to self-love, pride, and the snares of the devil.
By following these instructions you will avoid many dangers; for when the wily serpent sees the will of those who are aiming at the spiritual life to be strong and resolute, he attacks their understanding, that so he may master both the one and the other.
He often, therefore, infuses lofty and curious speculations into their minds, especially if they be of an acute and intellectual order, and easily inflated with pride; and he does this in order that they may busy themselves in the enjoyment and discussion of such subjects, wherein, as they falsely persuade themselves, they enjoy God, and meanwhile neglect to purify their hearts and to apply themselves to self-knowledge and true mortification. So, falling into the snare of pride, they make an idol of their own understanding.
Hence, being already accustomed to have recourse in all circumstances to their own judgment, they come gradually and imperceptibly to believe that they have no need of advice or control from others.
This is a most perilous case, and very hard to cure, the pride of the understanding being more dangerous than that of the will; for when the pride of the will is once perceived by the understanding, it may in course of time be easily remedied by submission to those to whom it owes obedience. But how, or by whom, can he be cured, who obstinately believes his own opinion to be worth more than that of others? How shall he submit to other men's judgment, which he accounts to be far inferior to his own!
The understanding is the eye of the soul, by which the wound of the proud will should be discovered and cleansed; if that eye, then, itself be weak and blind and swollen with pride, by whom shall it be healed?
And if the light become darkness, and the rule faulty, what will become of the rest?
Therefore resist this dangerous pride betimes, before it penetrate into the marrow of your bones.
Blunt the acuteness of your intellect, willingly submit your own opinion to that of others, become a fool for the love of God, and you shall be wiser than Solomon.
- taken from The Spiritual Combat, by Father Lorenzo Scupoli