“To him who has had the experience no explanation is necessary, to him who has not, none is possible.”

As quoted in Philippine Studies (1953) by Ateneo de Manila, p. 269; also in Everest : The Mountaineering History (2000) by Walt Unsworth, p. 100; but this has also been attributed to Ignatius of Loyola in Think of an Elephant : Combining Science and Spirituality for a Better Life (2007) by Paul Bailey http://books.google.com/books?id=1WWeHgqLoBkC&pg=PT299&dq=%22For+those+who+believe,+no+words+are+necessary%22&hl=en&sa=X&ei=LiGzUor6FdapsASYsYGgBA&ved=0CC4Q6AEwAA#v=onepage&q=%22For%20those%20who%20believe%2C%20no%20words%20are%20necessary%22&f=false
Disputed

Source: On the Kabbalah and Its Symbolism (1960), Ch. 1 : Religious Authority and Mysticism
Context: We shall start from the assumption that a mystic, insofar as he participates actively in the religious life of a community, does not act in the void. It is sometimes said, to be sure, that mystics, with their personal striving for transcendence, live outside of and above the historical level, that their experience is unrelated to historical experience. Some admire this ahistorical orientation, others condemn it as a fundamental weakness of mys­ticism. Be that as it may, what is of interest to the history of reli­gions is the mystic's impact on the historical world, his conflict with the religious life of his day and with his community. No his­torian can say — nor is it his business to answer such questions­ whether a given mystic in the course of his individual religious experience actually found what he was so eagerly looking for. What concerns us here is not the mystic's inner fulfillment. But if we wish to understand the specific tension that often prevailed between mysticism and religious authority, we shall do well to recall certain basic facts concerning mysticism.
A mystic is a man who has been favored with an immediate, and to him real, experience of the divine, of ultimate reality, or who at least strives to attain such experience. His experience may come to him through sudden illumination, or it may be the result of long and often elaborate preparations. From a historical point of view, the mystical quest for the divine takes place almost exclusively wit a prescribed tradition-the exceptions seem to be limited to modern times, with their dissolution of all traditional ties. Where such a tradition prevails, a religious authority, established long before the mystic was born, has been recognized by the com­ munity for many generations.

Peace on Earth (1987), tr. Elinor Ford (1994) from Pokój na Ziemi, Ch. 4

Source: The Future of the Mind: The Scientific Quest to Understand, Enhance, and Empower the Mind

Source: The Practice of the Presence of God

Source: The Montessori Method (1912), Ch. 1 : A Critical Consideration of the New Pedagogy in its Relation to Modern Science, p. 8.
Context: We give the name scientist to the type of man who has felt experiment to be a means guiding him to search out the deep truth of life, to lift a veil from its fascinating secrets, and who, in this pursuit, has felt arising within him a love for the mysteries of nature, so passionate as to annihilate the thought of himself. The scientist is not the clever manipulator of instruments, he is the worshipper of nature and he bears the external symbols of his passion as does the follower of some religious order. To this body of real scientists belong those who, forgetting, like the Trappists of the Middle Ages, the world about them, live only in the laboratory, careless often in matters of food and dress because they no longer think of themselves; those who, through years of unwearied use of the microscope, become blind; those who in their scientific ardour inoculate themselves with tuberculosis germs; those who handle the excrement of cholera patients in their eagerness to learn the vehicle through which the diseases are transmitted; and those who, knowing that a certain chemical preparation may be an explosive, still persist in testing their theories at the risk of their lives. This is the spirit of the men of science, to whom nature freely reveals her secrets, crowning their labours with the glory of discovery.
There exists, then, the "spirit" of the scientist, a thing far above his mere "mechanical skill," and the scientist is at the height of his achievement when the spirit has triumphed over the mechanism. When he has reached this point, science will receive from him not only new revelations of nature, but philosophic syntheses of pure thought.

Problemata: Preliminary Expectoration
1840s, Fear and Trembling (1843)
Context: An old proverb fetched from the outward and visible world says: "Only the man that works gets the bread." Strangely enough this proverb does not aptly apply in that world to which it expressly belongs. For the outward world is subjected to the law of imperfection, and again and again the experience is repeated that he too who does not work gets the bread, and that he who sleeps gets it more abundantly than the man who works. In the outward world everything is made payable to the bearer, this world is in bondage to the law of indifference, and to him who has the ring, the spirit of the ring is obedient, whether he be Noureddin or Aladdin, and he who has the world's treasure, has it, however he got it.

The Election in November 1860 (1860)