William of St Thierrey 
From Meditation 9
The struggle for understanding
The wretchedness that is in me, Lord, is at once so impenetrable and so extensive that I can neither examine it in detail nor survey the whole in all its amplitude. For even now, when I wish to speak and listen to you, O Lord my God, the fog of it blankets me, as it so often does, and prevents my seeing you clear or hearing you plain.
So it is that I am forever finding myself cast out of doors by my own conscience. Is it not a case of 'let the wicked be taken away lest he see the glory of God'? And when I struggle on without the light of understanding, groping my way towards my goal, the impulse of my ardent longing is blunted and broken, and from your heights I fall back into my depths - from you to me, and from me lower still.
And once the driving force of my best effort is exhausted, like so much dust thrown up off the face of the earth I am turned into the   plaything of the winds, blown this way and that by the fantasies of thought, and whim, and feeling, as multitudinous as the faces of men, of moments in time, of links in the chain of events. So while
your face is ever bent on  me in purposeful goodwill,  I in  my wretchedness am always gazing down at the dull earth, and yet so blind withal and lapped in darkness that I do not know how to, reach your presence - nor can I, save in as much as there is no hiding from the face of truth, which sees through all things whatsoever their condition. And so, leaving my gift before the altar, I take myself angrily in hand, rise up, and, lighting the lamp of the word of God, in wrath and bitterness of soul I enter the darkened house of my conscience, seeking to identify the source of this murk, this hateful fog that comes between me and the light of my heart.
At once – imagine this! – a plague of flies erupts in front of my eyes and virtually chases me out of my own private domain, the house of my conscience. I enter, however, as of right, only to be met by a swarm of thoughts so insolent, so indisciplined, so diverse and disorderly that the human heart that spawned them is powerless to sort them out. However, I prepare to sit in judgement on them. I order them to stand in front of me so that I can identify the particular features and the general type of each, in order to assign to each its place in my household.  But before I can make them out and distinguish between them, they scatter and, constantly switching places, seem to mock their would- be judge.