Rest, Sir J. Lubbock

Rest is not idleness, and to lie sometimes on the grass on a summer day listening to the murmur of water, or watching the clouds float across the sky, is hardly a waste of time.

- Sir J. Lubbock [The Use of Life (1894), ch. IV: Recreation]

Happiness, Aristotle

One swallow does not make a summer, neither does one fine day; similarly one day or brief time of happiness does not make a person entirely happy.

- Aristotle (384BC-322BC)

Universe, Bernard Bailey

When they discover the center of the universe, a lot of people will be disappointed to discover they are not it.

- Bernard Bailey (1916-1996)

Summer, Celia Thaxter

There shall be eternal summer in the grateful heart.

- Celia Thaxter (1835-1894)

Health, Thich Nhat Hanh

Keeping your body healthy is an expression of gratitude to the whole cosmos - the trees, the clouds, everything.

- Thich Nhat Hanh (1926- )

June, Charles A. Aïdé

Do you recall that night in June
Upon the Danube River;
We listened to the ländler-tune,
We watched the moonbeams quiver.

- Charles A. Aïdé, Danube River.

http://en.wikiquote.org/wiki/June

Universe, Johann Wolfgang von Goethe

We do not have to visit a madhouse to find disordered minds; our planet is the mental institution of the universe.

- Johann Wolfgang von Goethe (1749-1832)

Summer, Wallace Stevens

The summer night is like a perfection of thought.

- Wallace Stevens (1879-1955)