James Russell Lowell (1819–1891)

THEREFORE think not the Past is wise alone,

For Yesterday knows nothing of the Best,

And thou shalt love it only as the nest

Whence glory-wingèd things to Heaven have flown:

To the great Soul alone are all things known;

Present and future are to her as past,

While she in glorious madness doth forecast

That perfect bud, which seems a flower full-blown

To each new Prophet, and yet always opes

Fuller and fuller with each day and hour,

Heartening the soul with odor of fresh hopes,

And longings high, and gushings of wide power,

Yet never is or shall be fully blown

Save in the forethought of the Eternal One.