Final answer:
Rudyard Kipling uses antithesis in the stanza, exemplified by the lines contrasting engagement with different social groups while maintaining one's virtue and balancing the value of people.
Step-by-step explanation:
The poetic element that Rudyard Kipling uses in this stanza is antithesis. Antithesis occurs when two opposite ideas are put together in a sentence to achieve a contrasting effect. The lines that best support the use of antithesis are "If you can talk with crowds and keep your virtue, Or walk with kings -- nor lose the common touch" and "If all men count with you, but none too much". These lines contrast the ability to maintain one's moral integrity while engaging with different social groups and balancing the value of all people while not overvaluing anyone individual.