What is the purpose in beginning this speech with a reference to Abraham Lincoln?

Answer fast. read the excerpt below and answer the question. i will tell you the tale of my wanderings and of the “herculean” labors, as i may call them, which i endured only to find at last the oracle irrefutable. socrates’ use of the word “herculean” in this excerpt from the apology is an example of what literary device? allusion metaphor onomatopoeia simile