Third Week after Epiphany.
"On recollection and union with God" part 2. From "The Way that leads to God - Practical counsels for those who aspire after true piety" by Abbot A. Saudreau, R&T Washbourne, LTD 1911.

2. Conflict with useless thoughts
90. What ceaseless vigilance is necessary for those who desire to live the life of faith! They must repress the activity of the mind, struggle against the flood of idle thoughts which invade it in spite of themselves, and preserve interior silence - a much more difficult and more important achievement than the silence which is exterior. This is the great battle which all souls aspiring after the perfect life must fight, and those who fight it ill can never live the life of faith, will never attain to perfection. Many and diverse are the thoughts which come to harass the poor human mind; those minor incidents of life - things which have no importance whatsoever, and which we ought to forget as soon as they have passed - return incessantly to our memories, suggesting the most useless reflections. We are occupied about things which we cannot alter; our neighbour's mistakes, his blunders, his wrongdoings, excite our indignation. Instead of asking God to enlighten our brethren and to correct their faults, we sit in judgment upon them in our minds. Politics also furnish their contingent of idle thoughts, for the march of events is not affected by our cogitations. But, more than any others, personal things are the chief source of our idle thinking. We occupy ourselves with criticism which may have been passed upon us, or which we might encounter in the future, or with the praise which we fancy that we deserve; we think how we might have acted on some bygone occasion and what the results would have then have been. And how tenacious and deeply rooted these vain thoughts are! Expel them, and back they come again, like importunate flies which will not be driven away; they renew their buzzing, repeating incessantly what they have already said.
And even when our reflections are legitimate, they often become useless when prolonged. To reflect upon the best means to of performing our duty, to consider the proper steps to be taken, to weight the consequences of our actions, is certainly commendable. But when once we have reviewed the circumstances and decided our course of action, a repetition of the same process becomes idle, and it is usually a sign that the individual is more concerned as to his personal success or possible humiliations than with the desire to please God. If half an hour's reflection is sufficient, and then for half a day we go over and over the same objections, giving the identical replies; if we fall back incessantly into the same preoccupations; of we constantly hold up to ourselves the same hopes - what precious time shall we not have lost?
91. Everyone allows that this mental labour is generally useless, and all fervent souls recognize and deplore the fact that it is very prejudicial to any advance in virtue. There are few, however, who will bring to bear the courage and energy necessary for its curtailment. The mortification of the imagination or of the memory is rarer that the practice of bodily austerities, little as this is understood; and the reason is that it is even more difficult and painful. The maxims of St. Francis of Assisi and St. Ignatius - "Be like a corpse" (Perinde ac cadaver) - might be applied here, with a slight variation of its original sense. Be dead to all earthly things - to all those, at any rate, with which you have no concern, or which you have no power to change. To all that happens give only the least possible measure of your attention, sufficient to enable you to fulfil your social duties and to prevent you appearing as an alien amongst your fellow-men. Fix your thoughts on such things only as you are responsible for, and even here let there be no disturbance and anxiety. And, finally, direct your mind, emptied of all earthly thoughts, towards the things of God.

Next: How the mind should be nourished with the Holy Thoughts.