“Noon sits at the Master's right hand, Dawn at his left. Dusk stands behind, in the shadows. Yet sometimes it is easier to see the light when you stand partly in the darkness.”

The Notebooks of Leonardo da Vinci (1883), III Six books on Light and Shade

Source: The Song of Achilles

Source: Skin Game

Though "the Bard" is often reference to William Shakespeare, Fuller here probably uses the term in a generic sense, and in tribute to the poet-philosopher she considered in some ways her mentor, Ralph Waldo Emerson, who may have made such a statement, which she elsewhere quotes as "I have witnessed many a shipwreck, yet still beat noble hearts".
Woman in the Nineteenth Century (1845)
Context: I stand in the sunny noon of life. Objects no longer glitter in the dews of morning, neither are yet softened by the shadows of evening. Every spot is seen, every chasm revealed. Climbing the dusty hill, some fair effigies that once stood for symbols of human destiny have been broken; those I still have with me show defects in this broad light. Yet enough is left, even by experience, to point distinctly to the glories of that destiny; faint, but not to be mistaken streaks of the future day. I can say with the bard,
"Though many have suffered shipwreck, still beat noble hearts."
Always the soul says to us all, Cherish your best hopes as a faith, and abide by them in action. Such shall be the effectual fervent means to their fulfilment.

The Enemy of Europe (1953)

Source: Hainish Cycle, The Left Hand of Darkness (1969), Chapter 16 “Between Drumner and Dremegole” (p. 233)

Source: The Hollow Hills

The Education of Henry Adams (1907)

Nets to Catch the Wind (1921), A Crowded Trolley Car