"In the world, when people call anyone simple, they generally mean a foolish, ignorant, credulous person. But real simplicity, so far from being foolish, is almost sublime. All good men like and admire it, are conscious of sinning against it, observe it in others and know what it involves; and yet they could not precisely define it. I should say that simplicity is an uprightness of soul which prevents self-consciousness. It is not the same as sincerity, which is a much humbler virtue. Many people are sincere who are not simple. They say nothing but what they believe to be true, and do not aim at appearing anything but what they are. But they are forever thinking about themselves, weighing their every word and thought, and dwelling upon themselves in apprehension of having done too much or too little. These people are sincere but they are not simple. They are not at their ease with others, nor others with them. There is nothing easy, frank, unrestrained or natural about them. One feels that one would like less admirable people better, who were not so stiff.
To be absorbed in the world around and never turn a thought within, as in the blind condition of some who are carried away by what is pleasant and tangible, is one extreme as opposed to simplicity. And to be self-absorbed in all matters, whether it be duty to God or man, is the other extreme, which makes a person wise in his own conceit – reserved, self-conscious, uneasy at the least thing which disturbs his inward self-complacency. Such false wisdom, in spite of its solemnity, is hardly less vain and foolish than the folly of those who plunge headlong into worldly pleasures. The one is intoxicated by his outward surroundings, the other by what he believes himself to be doing inwardly; but both are in a state of intoxication, and the last is a worse state than the first, because it seems to be wise, though it is not really, and so people do not try to be cured. Real simplicity lies in a just milieu equally free from thoughtlessness and affectation, in which the soul is not overwhelmed by externals, so as to be unable to reflect, nor yet given up to the endless refinements, which self-consciousness induces. The soul which looks where it is going without losing time arguing over every step, or looking back perpetually, possesses true simplicity. Such simplicity is indeed a great treasure. How shall we attain to it? I would give all I possess for it; it is the costly pearl of Holy Scripture.
The first step, then, is for the soul to put away outward things and look within so as to know its own real interest; so far all is right and natural; thus much is only wise self-love, which seeks to avoid the intoxication of the world.
In the next step the soul must add the contemplation of God, whom it fears, to that of self. This is a faint approach to the real wisdom, but the soul is still greatly self-absorbed; it is not satisfied with fearing God; it wants to be certain that it does fear him and fears lest it fears him not, going round in a perpetual circle of self-consciousness. All this restless dwelling on self is very far from the peace and freedom of real love; but that is yet in the distance; the soul needs to go through a season of trial, and were it suddenly plunged into a state of rest, it would not know how to use it.
The third step is that, ceasing from a restless self-contemplation, the soul begins to dwell upon God instead, and by degrees forgets itself in Him. It becomes full of Him and ceases to feed upon self. Such a soul is not blinded to its own faults or indifferent to its own errors; it is more conscious of them than ever, and increased light shows them in plainer form, but this self-knowledge comes from God, and therefore it is not restless or uneasy."
– Francois Fenelon, quoted in The Perennial Philosophy