“Whether we wake or we sleep,
Whether we carol or weep,
The Sun with his Planets in chime,
Marketh the going of Time.”

p, 125
Geometrical Lectures (1735)

The House of Dust (1916 - 1917)

The statement "The future of all life, including our own, depends on our mindful steps." and much of the theme of this essay also occur later in his writings, including The World We Have : A Buddhist Approach to Peace and Ecology (2008), Ch. 1 : The Bells of Mindfulness, p. 3
The Sun My Heart (1996)
Context: All life is impermanent. We are all children of the Earth, and, at some time, she will take us back to herself again. We are continually arising from Mother Earth, being nurtured by her, and then returning to her. Like us, plants are born, live for a period of time, and then return to the Earth. When they decompose, they fertilize our gardens. Living vegetables and decomposing vegetables are part of the same reality. Without one, the other cannot be. After six months, compost becomes fresh vegetables again. Plants and the Earth rely on each other. Whether the Earth is fresh, beautiful, and green, or arid and parched depends on the plants.
It also depends on us. Our way of walking on the Earth has a great influence on animals and plants. We have killed so many animals and plants and destroyed their environments. Many are now extinct. In turn, our environment is now harming us. We are like sleepwalkers, not knowing what we are doing or where we are heading. Whether we can wake up or not depends on whether we can walk mindfully on our Mother Earth. The future of all life, including our own, depends on our mindful steps.

Separation has this lofty meaning...

"Rococo", lines 17-24.
Poems and Ballads (1866-89)

"Remarks in Newport at the Australian Ambassador's Dinner for the America's Cup Crews (383)" (14 September 1962) http://www.jfklibrary.org/Research/Research-Aids/Ready-Reference/JFK-Quotations.aspx<!-- Public Papers of the President: John F. Kennedy, 1962 -->
1962
Context: I really don't know why it is that all of us are so committed to the sea, except I think it's because in addition to the fact that the sea changes, and the light changes, and ships change, it's because we all came from the sea. And it is an interesting biological fact that all of us have, in our veins the exact same percentage of salt in our blood that exists in the ocean, and, therefore, we have salt in our blood, in our sweat, in our tears. We are tied to the ocean. And when we go back to the sea — whether it is to sail or to watch it — we are going back from whence we came.

Science and Immortality (1904)
Context: Though his philosophy finds nothing to support it, at least from the standpoint of Terence the scientific student should be ready to acknowledge the value of a belief in a hereafter as an asset in human life. In the presence of so many mysteries which have been unveiled, in the presence of so many yet unsolved, he cannot be dogmatic and deny the possibility of a future state; and however distressing such a negative attitude of mind to the Teresian, like Pyrrho, he will ask to be left, reserving his judgement, but still inquiring. He will recognize that amid the turbid ebb and flow of human misery, a belief in the resurrection of the dead and the life of the world to come is the rock of safety to which many of the noblest of his fellows have clung; he will gratefully accept the incalculable comfort of such a belief to those sorrowing for precious friends hid in death's dateless night; he will acknowledge with gratitude and reverence the service to humanity of the great souls who have departed this life in a sure and certain hope but this is all. Whether across death's threshold we step from life to life, or whether we go whence we shall not return, even to the land of darkness, as darkness itself, he cannot tell.

2021, Response to COP26 (November 2021)
Source: Quoted in “‘You can shove your climate crisis up your arse’: Greta Thunberg sings at Cop26 – video” https://www.theguardian.com/environment/video/2021/nov/02/you-can-shove-your-climate-crisis-up-your-arse-greta-thunberg-sings-at-cop26-video, The Guardian (2 November 2021)

Quoted in "The Columbia Dictionary of Quotations" - Page 446 - by Robert Andrews - Reference - 1993.