“Many of the dead very considerably retard the process of dissolution by clinging passionately to the earth which they have left; they simply will not turn their thoughts and desires upward, but spend their time in struggling with all their might to keep in full touch with the physical plane, thus causing great trouble to any one who may be trying to help them. Earthly matters are the only ones in which they have had any living interest, and they cling to them with desperate tenacity even after death. Naturally as time passes on they find it increasingly difficult to keep hold of things down here, but instead of welcoming and encouraging this process of gradual refinement and spiritualization they resist it vigorously by every means in their power… thereby not only causing themselves a vast amount of entirely unnecessary pain and sorrow, but also very seriously delaying their upward progress and prolonging their stay in astral regions to an almost indefinite extent. In convincing them that this ignorant and disastrous opposition to the cosmic will is contrary to the laws of nature, and persuading them to adopt an attitude of mind which is the exact reversal of it, lies a great part of the work of those who are trying to help.”

P.A.M. Dirac, "Pretty Mathematics," International Journal of Theoretical Physics, Vol. 21, Issue 8–9, August 1982, p. 603 http://link.springer.com/article/10.1007/BF02650229#page-1

Harvard University address (1978)
Context: Even if we are spared destruction by war, our lives will have to change if we want to save life from self-destruction. We cannot avoid revising the fundamental definitions of human life and human society. Is it true that man is above everything? Is there no Superior Spirit above him? Is it right that man's life and society's activities have to be determined by material expansion in the first place? Is it permissible to promote such expansion to the detriment of our spiritual integrity?
If the world has not come to its end, it has approached a major turn in history, equal in importance to the turn from the Middle Ages to the Renaissance. It will exact from us a spiritual upsurge, we shall have to rise to a new height of vision, to a new level of life where our physical nature will not be cursed as in the Middle Ages, but, even more importantly, our spiritual being will not be trampled upon as in the Modern era.
This ascension will be similar to climbing onto the next anthropologic stage. No one on earth has any other way left but — upward.

Section 13
The True Believer (1951), Part One: The Appeal of Mass Movements

Source: A Woman's Thoughts About Women (1858), Ch. 10

Source: Silas Marner: The Weaver of Raveloe (1861), Chapter 8 (at page 63)

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 182.

III, 4210-11
Jewels of Remembrance (1996)

1920s, The Genius of America (1924)
Context: It is the natural and correct attitude of mind for each of us to have regard for our own race and the place of our own origin. There is abundant room here for the preservation and development of the many divergent virtues that are characteristic of the different races which have made America their home. They ought to cling to all these virtues and cultivate them tenaciously. It is my own belief that in this land of freedom new arrivals should especially keep up their devotion to religion. Disregarding the need of the individual for a religious life, I feel that there is a more urgent necessity, based on the requirements of good citizenship and the maintenance of our institutions, for devotion to religion in America than anywhere else in the world. One of the greatest dangers that beset those coming to this country, especially those of the younger generation, is that they will fall away from the religion of their fathers, and never become attached to any other faith.