“It is essential that we realize once and for all that man is much more of a sex creature than a moral creature. The former is inherent, the other is grafted on.”

Source: The Secret Scripture

Epigraph, The Thorn Birds (1977)
Context: There is a legend about a bird that sings just once in its life, more sweetly than any other creature on the face of the earth. From the moment it leaves the nest it searches for a thorn tree and does not rest until it has found one. Then, singing among the savage branches, it impales itself upon the longest, sharpest spine. Dying, it rises above its own agony to out-carol the lark and the nightingale. One superlative song, existence the price. But the whole world stills to listen, and God in His heaven smiles. For the best is only bought at the cost of the great pain. … Or so says the legend.

XVII. 446–447 (tr. R. Lattimore); Zeus.
Robert Fagles's translation:
: There is nothing alive more agonized than man
of all that breathe and crawl across the earth.
Iliad (c. 750 BC)

Source: What Is Man? (1906), Ch. 6

No. 494 (26 September 1712).
The Spectator (1711–1714)

From Anacreon, ii. Drinking; reported in Bartlett's Familiar Quotations, 10th ed. (1919).

D 58
The proof that man is the noblest of all creatures is that no other creature has ever denied it.
Aphorisms (1765-1799), Notebook D (1773-1775)

The Message in the Bottle (1975)

As quoted in "From Wing Chun to Jeet Kune Do" by Jesse R. Glover in Black Belt Vol. 31, No. 9 (September 1993), p. 35