An End (purpose) (n.) is what people name after they have already chosen the means.
The End (purpose) (n.) is not a justifaction of the means; it is the means.
The Final end (n.) must be desirable on its own account: ask why a man exercises — for health; why health — sickness is painful; why he hates pain — and he can give no reason.
A Mission (n.) is what work calls itself when quitting would feel like treason.
A National purpose (n.) that history never once met is, by definition, safe from refutation, like a religion that survives its believers' sins.