What is the significance of the inscription at Delos in Book I?

Aristotle cites the inscription at Delos as further justification for his conviction that happiness is the final and ultimate good of human beings. It reads: “Most noble is that which is justest, and best is health; but pleasantest is it to win what we love.” Crucially, for Aristotle, human beings are by nature desirers of happiness. This natural orientation is what grounds the ultimate good as happiness.