4 I have narrated the event: listen now, if you please, to my question, and teach me what I ask, for the departure of that young man's soul forces such questions from me. While we are in the body, we have an inward faculty of perception which is alert in proportion to the activity of our attention, and is more wakeful and eager the more earnestly attentive we become: and it seems to us probable that even in its highest activity it is retarded by the encumbrance of the body, for who can fully describe all that the mind suffers through the body!
In the midst of the perturbation and annoyance which come from the suggestions, temptations, necessities, and varied afflictions of which the body is the cause, the mind does not surrender its strength, it resists and conquers. Sometimes it is defeated; nevertheless, mindful of what is its own nature, it becomes, under the stimulating influence of such labours, more active and more wary, and breaks through the meshes of wickedness, and so makes its way to better things. Your Holiness will kindly understand what I mean to say.
Therefore, while we are in this life, we are hindered by such deficiencies, and are nevertheless, as it is written, “more than conquerors through Him that loved us.” When we go forth from this body, and escape from every burden, and from sin, with its incessant activity, what are we?
Source: Letters (New Advent)