In the poem “If—”, why does Kipling say “If you can… don't deal in lies”?

The first verse reads as follows:

If you can wait and not be tired by waiting,
Or, being lied about, don’t deal in lies,
Or, being hated, don’t give way to hating,
And yet don’t look too good, nor talk too wise...

My question is: why "don't", not "not" like in the first string or in the second verse (If you can dream—and not make dreams your master; // If you can think—and not make thoughts your aim...).

Thank you.