The Undiscovered Country Poem by Ella Wheeler Wilcox

Man has explored all countries and all lands,
And made his own the secrets of each clime.
Now, ere the world has fully reached its prime,
The oval earth lies compassed with steel bands,
The seas are slaves to ships that touch all strands,
And even the haughty elements sublime
And bold, yield him their secrets for all time,
And speed like lackeys forth at his commands.

Still, though he search from shore to distant shore,
And no strange realms, no unlocated plains
Are left for his attainment and control,
Yet is there one more kingdom to explore.
Go, know thyself, O man! there yet remains
The undiscovered country of thy soul!