The motivation in the case shifts from the ground of material interest to the spiritual ground of the moral sentiments.
In this connection "honour" is of course to be taken in the euphemistic sense which the term has under the _code duello_ governing "affairs of honour." It carries no connotation of honesty, veracity, equity, liberality, or unselfishness.

This national honour is of the nature of an intangible or immaterial asset, of course; it is a matter of prestige, a sportsmanlike conception; but that fact must not be taken to mean that it is of any the less substantial effect for purposes of a _casus belli_ than the material assets of the community.

Quite the contrary: "Who steals my purse, steals trash," etc.

In point of fact, it will commonly happen that any material grievance must first be converted into terms of this spiritual capital, before it is effectually turned to account as a stimulus to warlike enterprise.
Even among a people with so single an eye to the main chance as the American community it will be found true, on experiment or on review of the historical evidence, that an offense against the national honour commands a profounder and more unreserved resentment than any infraction of the rights of person or property simply.

This has latterly been well shown in connection with the manoeuvres of the several European belligerents, designed to bend American neutrality to the service of one side or the other.