“A fresh mind keeps the body fresh. Take in the ideas of the day, drain off those of yesterday. As to the morrow, time enough to consider it when it becomes to-day.”

The Figure a Poem Makes (1939)
Context: Like a piece of ice on a hot stove the poem must ride on its own melting … Read it a hundred times; it will forever keep its freshness as a metal keeps its fragrance. It can never lose its sense of a meaning that once unfolded by surprise as it went.

1970s, You are the World (1972)
Context: Now, can one die every day to everything that one knows — except, of course, the technological knowledge, the direction where your home is, and so on; that is, to end, psychologically, every day, so that the mind remains fresh, young and innocent? That is death. And to come upon that there must be no shadow of fear. To give up without argument, without any resistance. That is dying. Have you ever tried it? To give up without a murmur, without restraint, without resistance, the thing that gives you most pleasure (the things that are painful, of course, one wants to give up in any case). Actually to let go. Try it. Then, if you do it, you will see that the mind becomes extraordinarily alert, alive and sensitive, free and unburdened. Old age then takes on quite a different meaning, not something to be dreaded.<!-- p. 135

Source: Chinese Cinderella and the Secret Dragon Society

Simplicity http://www.poetrysoup.com/famous/poem/21390/Simplicity
From the poems written in English

1880s, Garfield's Words (1882)
Context: I must do something to keep my thoughts fresh and growing. I dread nothing so much as falling into a rut and feeling myself becoming a fossil.

As quoted in French Writers of the Past (2000) by Carol A. Dingle, p. 127

Introductory Lecture on Experimental Physics held at Cambridge in October 1871, re-edited by W. D. Niven (2003) in Volume 2 of The Scientific Papers of James Clerk Maxwell, Courier Dover Publications, p. 241; this has sometimes been misquoted in a way which considerably alters its intent: "in a few years, all the great physical constants will have been approximately estimated, and … the only occupation which will then be left to the men of science will be to carry these measurement to another place of decimals."
Context: This characteristic of modern experiments — that they consist principally of measurements — is so prominent, that the opinion seems to have got abroad, that in a few years all the great physical constants will have been approximately estimated, and that the only occupation which will then be left to men of science will be to carry on these measurements to another place of decimals. If this is really the state of things to which we are approaching, our Laboratory may perhaps become celebrated as a place of conscientious labour and consummate skill, but it will be out of place in the University, and ought rather to be classed with the other great workshops of our country, where equal ability is directed to more useful ends.
But we have no right to think thus of the unsearchable riches of creation, or of the untried fertility of those fresh minds into which these riches will continue to be poured. It may possibly be true that, in some of those fields of discovery which lie open to such rough observations as can be made without artificial methods, the great explorers of former times have appropriated most of what is valuable, and that the gleanings which remain are sought after, rather for their abstruseness, than for their intrinsic worth. But the history of science shews that even during the phase of her progress in which she devotes herself to improving the accuracy of the numerical measurement of quantities with which she has long been familiar, she is preparing the materials for the subjugation of the new regions, which would have remained unknown if she had been contented with the rough methods of her early pioneers. I might bring forward instances gathered from every branch of science, shewing how the labour of careful measurement has been rewarded by the discovery of new fields of research, and by the development of new scientific ideas. But the history of the science of terrestrial magnetism affords us a sufficient example of what may be done by experiments in concert, such as we hope some day to perform in our Laboratory.