Now, let us go further and penetrate even into the depths of this soul whose features we are sketching. Thoughts play a most important part in the supernatural, as well as in the moral and intellectual life. Now what are the thoughts that occupy this man, and what direction do they take? Human, earthly, vain, superficial, and egotistical, they converge more and more upon self or upon creatures, and that, sometimes, with every appearance of devotion to duty and of sacrifice. This disorder in the mind brings with it a corresponding unruliness in the imagination. Of all our powers, this one is the most in need of being repressed at this stage. And yet it never even occurs to him to put on the brakes! Therefore, having free rein, it runs wild. No exaggeration, no madness, is too much for it. And the progressive suppression of all mortification of the eyes soon gives this crazy tenant of his soul opportunities to forage wherever it wills, in lush pastures!As Dom Chautard said earlier, "Everything links up. Deep calls to deep." Or, as Holy Mother Church has solemnly repeated throughout the ages, "How we pray affects how we believe and how we live."
Defects in one's prayer life has detrimental effects on how a person thinks. Indeed, it creates a disorder that spreads into other aspects of one's prayer life, as Dom Chautard has illustrated elsewhere.
Friends, have we allowed proud, vain, superficial and egotistical thoughts (admittedly hard to separate from one another) to invade our prayer life? Have we let our imagination run wild with what we think we are capable of doing - to the point where our planned actions and ideas are unattainable simply because of the height they are at?
Dom Chautard's last sentence here seem to refer to the consumption of knowledge that a soul has no right to know - "suppression of all mortification of the eyes" and "forag[ing] ... in lush pastures" - and this in turn feeds the imagination to assume such lofty heights and thus despoil otherwise lush pastures. It is a firm warning if that is what it means.
If anyone has another interpretation of the last sentence, suggestions are welcome in the combox.