Know Then Thyself by Alexander Pope (1688-1744)

Know then thyself, presume not God to scan 
The proper study of Mankind is Man. 
Plac'd on this isthmus of a middle state 
A Being darkly wise, and rudely great:

With too much knowledge for the Skeptic side,
With too much weakness for the Stoic's pride,
He hangs between; in doubt to act, or rest;
In doubt to deem himself a God, or Beast;
In doubt his Mind or Body to prefer;
Born but to die, and reas'ning but to err;

Alike in ignorance, his reason such,
Whether he thinks too little, or too much:
Chaos of Thought and Passion, all confus'd
Still by himself abus'd, or disabus'd;
Created half to rise, and half to fall;
Great lord of all things, yet a prey to all;
Sole judge of truth, in endless error hurl'd:
The glory, jest, and riddle of the world!