Jean Pierre de Caussade is a great teacher of silent prayer and a more complex and, perhaps, subtle expositor of the "Practice of the Presence of God," as conceived by Brother Lawrence of the Resurrection. Many have accused de Caussade of Quietism, but over the years that accusation has been addressed and disproved. What de Caussade teaches is not fatalistic resignation, but enthusiastic conformity to God's will.
Perfection consists in doing the will of God, not in understanding His designs.
The designs of God, the good pleasure of God, the will of God, the operation of God and the gift of His grace are all one and the same thing in the spiritual life. It is God working in the soul to make it like unto Himself. Perfection is neither more nor less than the faithful co-operation of the soul with this work of God, and is begun, grows, and is consummated in the soul unperceived and in secret. The science of theology is full of theories and explanations of the wonders of this state in each soul according to its capacity. One may be conversant with all these speculations, speak and write about them admirably, instruct others and guide souls; yet, if these theories are only in the mind, one is, compared with those who, without any knowledge of these theories, receive the meaning of the designs of God and do His holy will, like a sick physician compared to simple people in perfect health.
There seems to be a certain stream of anti-intellectualism here, but I think it is only seeming. De Caussade, as with any good Christian, does not encourage merely intellectual assent, but actual action based on what is called for in the present moment. His theory, which I believe to be correct, is that understanding the reasons of God is not nearly so important as willingly doing those things that God requests.
Perfection is not perfection of intellect, rather a perfection of duty and activity, even if that activity consists in sitting at Jesus' feet.
The soul that does not attach itself solely to the will of God will find neither satisfaction nor sanctification in any other means however excellent by which it may attempt to gain them. If that which God Himself chooses for you does not content you, from whom do you expect to obtain what you desire? If you are disgusted with the meat prepared for you by the divine will itself, what food would not be insipid to so depraved a taste? No soul can be really nourished, fortified, purified, enriched, and sanctified except in fulfilling the duties of the present moment. What more would you have? As in this you can find all good, why seek it elsewhere? Do you know better than God? As he ordains it thus why do you desire it differently? Can His wisdom and goodness be deceived? When you find something to be in accordance with this divine wisdom and goodness ought you not to conclude that it must needs be excellent? Do you imagine you will find peace in resisting the Almighty? Is it not, on the contrary, this resistance which we too often continue without owning it even to ourselves which is the cause of all our troubles?
And I think the wisdom of this passage is apparent without going into any detail. Those who would resist God's love, God's Teaching through His Church, and God's infinite outreach, resist peace itself. They struggle to upset their own peace, thinking it merely complacency, and having dragged themselves out of it, think it their duty to drag everyone else out as well. Such are the dissenters, the supposed intellectual heroes of the resistance movement, who abandoning God's peace, choose peace only on their own terms. To them, I simply ask the question presented in the second sentence above, "If God's will is not good enough, what will you find that is?"