Here are 16 principles that I gathered from The Intellectual Life by A.G. Sertillanges along with quotes. I must have underlined at least half of the book!
And really, I gathered these principles so that I could remember them for myself. This book made me realize I need to make some changes -- a lot of them!
1. Love truth and be committed to finding truth, which is always practical and redemptive.
"We must give ourselves from the heart, if truth is to give itself to us."
"A true Christian will have ever before his eyes the image of this globe, on which the Cross is planted, on which needy men wander and suffer, all over which the redeeming Blood, in numberless streams, flows to meet them...Every truth is practical...Every truth is life, direction, a way leading to the end of man. And therefore Jesus Christ made this unique assertion: 'I am the Way, the Truth, and the Life.'"
"Truth visits those who love her, who surrender to her..."
"The source of knowledge is not in books, it is in reality, and in our thought. Books are signposts: the road is older, and no one can make the journey to truth for us. It is not what a writer says that is of first importance to us; the important thing is what is.2. If you can, keep two hours a day for the development of your mind.
"You, young man who understand this language and to whom the heroes of the mind seem mysteriously to beckon, but who fear to lack the necessary means, listen to me. Have you two hours a day? Can you under to keep them jealously, to use them ardently...?"3. Be pure.
"Now, passions and vices relax attention, scatter it, lead it astray; and they injure the judgment in roundabout ways..."
"To calm our passions is to awake in ourselves the sense of the universal; to correct ourselves is to bring out the sense of the true."
"Purity of thought requires purity of soul; that is a general and undeniable truth."
"Intemperance is a sin because it destroys us; and we have the obligation to use life wisely because we have the obligation to live."4. Accept yourself.
"To accept ourselves as we are is to obey God and to make sure of good results. Does nature seek to exceed her powers?"
"Seek the approval of God; be intent only on truth, for yourself and others; do not be a slave; make yourself worthy to say with Paul: 'The word of God is not bound.'"
"Altiora te ne quaesieris, do not seek the things above you." - Thomas Aquinas
"You alone can do well what is laid upon you; you would do badly what your neighbor will do well. God is satisfied in all."
"When a reproach is leveled at you, instead of rebelling interiorly or exteriorly like an animal bristling up, observe like a man the bearing of what is said; be impersonal and honest. If the criticism is right and you wrong, do you mean to resist truth?"5. Cultivate a spirit of prayer and eternity while studying.
"Every study is a study of eternity." - Van Helmont
"Intelligence only plays its part fully when it fulfills a religious function, that is, when it worships the supreme Truth in its minor and scattered appearances."6. Take care of yourself physically.
"Live as much as possible in the open air...Windows open or partly open day and night when prudence allows, frequent deep breathing exercises, combined with movements that amplify them and make them normal, walks before and after work or even combined with work according to the Greek tradition; all these practices are excellent."
"Those who do not find time to take exercise must find time to be ill."
"Look after your diet. Light food, plain, moderate in quantity and simply cooked, will enable you to work more freely and alertly."7. Simplify your life.
"If you want to entertain knowledge as your guest, you do not need rare furniture, nor numerous servants. Much peace, a little beauty, certain conveniences that save time, are all that is necessary."
"Money and attention squandered on trifles would be much better spent in collecting a library, providing for instructive travel or restful holidays, going to hear music which rekindles inspiration, and so on."8. Be silent. Seek silence.
"Therefore, be slow to speak and slow to go to those places where people speak, because in many words the spirit is poured out like water; by your amiability to all, purchase the right really to frequent only a few whose society is profitable; avoid, even with these, the excessive familiarity which drags one down and away from one's purpose; do not run after news that occupies the mind to no purpose; do not busy yourself with the sayings and doings of the world, that is with such as have no moral or intellectual bearing; avoid useless comings and goings which waste hours and fill the mind with wandering thoughts. These are the conditions of that sacred thing, quiet recollection."
"Before giving out truth, acquire it for yourself..."9. Rest truly.
"When evening comes, [most people] lay down the reins and throw off thought, giving their minds up to dissipation which is supposed to refresh them, dining, smoking, playing cards, talking noisily, frequenting the theaters or the music halls, gaping at the cinemal, and going to bed with minds 'relaxed.' Yes, indeed, relaxed; but like a violin with all its strings completely slackened. What a labor next day to tune them all up again! I know industrialists who find their relaxation in reading Pascal, Montaigne, Ronsard, Racine. Deep in a comfortable armchair well lit from behind, beside the fire, their family around them, quiet, or in the buzz of pleasant activity, they live awhile after having toiled all day."
"In spite of the passionate and self-interested illusion of those who maintain that a part of man must be set aside for the life of pleasure, dissipation is not rest, it is exhaustion. Rest cannot be found in scattering one's energies. Rest means giving up all effort and withdrawing towards the fount of life; it means restoring our strength, not expending it foolishly."10. Be zealous to know and concentrate.
"Half-work, which is half-rest, is good neither for rest nor for work."
"Many thinkers have found habitual relief and attraction in stories of travel and exploration, in poetry, art criticism, reading of plays, memoirs. Each one has his tastes, and taste in this matter is the capital thing. One thing alone according to St. Thomas gives real rest: joy; to seek distraction in something boring would be a delusion."
"The intelligence is like a child, whose lips never cease their why."
"The great enemy of knowledge is our indolence; that native sloth which shrinks from effort..."
"Let each taste take entire hold of you, as if it were the only one."11. Read that which will edify your mind.
"What we are proscribing is the passion for reading, the uncontrolled habit, the poisoning of the mind by excess of mental food, the laziness in disguise which prefers easy familiarity with others' thought to personal effort."
"The mind is dulled, not fed, by inordinate reading, it is made gradually incapable of reflection and concentration, and therefore of production..."
"The wise worker, preserving his self-control, calm and clear-headed, reads only what he wants to retain, retains only what will be useful, manages his brain prudently and does not abuse it by cramming it absurdly."
"Choose your books. Do not trust interested advertising and catchy titles. Have devoted and expert advisers."12. Read the book inside yourself.
"In ourselves also there are volumes and texts of great value that we do not read."
"Truth is all men's ancestor; wisdom addresses her invitation to all; we must not leave to the greatest the monopoly of making a superior use of what is offered us."
"It is my duty to be myself. What is the good of repeating others? However unimportant I am, I know that God makes none of His spiritual beings without a purpose -- He does not make the least natural object without a purpose. I am obeying my Master by setting myself free. I am alive, I am not a mere reflection, and I want to live a fruitful life."
"A book is a signal, a stimulant, a helper, an initiator -- it is not a substitute and it is not a chain. Our thought must be what we ourselves are."13. Be at peace so that you may remember.
"Agitation of mind is opposed to this operation [of memory], and therefore a peaceful life, passion-free, is necessary for the good use of memory as for all the intellectual functions."
"Keep your inspiration lofty, your attention keen; be sensitively responsive to truth, be eager in research, and you will remember enough."14. Take some notes.
"Notes, which are a sort of external memory, a 'paper memory' Montaigne called them, must bear a very small proportion to reading; but they can cover more ground than memory, they can supply for it, and so take the strain off it and help our work in a measure that is hard to assign."
"Keep notes made after thinking, and with moderation."
"Reading itself should awaken reflection, and we have already said that a borrowed passage can become our own to the point of not differing at all from an original creation. I read, and I write while reading; but I write down what I think after contact with someone else..."15. Write in the light of truth, individuality, and simplicity.
"To speak is to listen to one's soul and to the truth within it. To speak alone and wordlessly, as one does by writing, is to listen and perceive with a freshness of sensation like that of a man who rises in the early morning and holds his ear to nature."
"The qualities of style may be set out under as many headings as you will; but they can all be contained, I think, in these three words: truth, individuality, and simplicity; unless you prefer to sum it all up in a single formula; one must write truly."
"Embellishment is an offense against thought, unless it be an expedient to conceal its void."
"The beautiful is the removal of all superfluity." - Michelangelo16. Work when you are sad.
"In knowledge, as in everything, one attains salvation only through the cross. Dissatisfaction with oneself, sluggishness of inspiration, the indifference of those about one, envy, misunderstandings, sarcastic remarks, acts of injustice, the desertion of leaders, the faling-away of friends, all these things can be part of the cross, and all of them come in their turn."
"Work cures the pain of work and those of the worker; it is the foe of annoyances, sickness, and sin; it lifts us into a high region where the vexations of life and the weaknesses of the body find alleviation. The urge it rouses, the direction it gives to our energy, are an anodyne for worry and release us from wretched preoccupations."
"When I ask myself what remedy I shall use against the fits of anxiety and dullness that come over me in my work, I find only one answer: work. What stimulus can I find for my courage, if I lose heart about my work? Work...Work is the remedy, work is the balm, work carries me along through every trial. Add to work its companion, silence, and its inspiration, prayer..."
"Sadness and doubt kill inspiration; but they kill it only when one yields to them. To rise above them by Christian joy is to rekindle the drooping flame."