People make light of honor, the most basic form of which is keeping one’s word. Imagine a society in which no one could be relied on to mean what they say. It would be as significant as a loss of gravity, and perhaps less survivable. And we don’t decide these things only collectively, where someone else always shoulders the burden when we fail, but each individual makes the effort in concert with society. Keeping one’s word is the most basic sign that one is fit to live among people.