A soldier is a yahoo hired to kill in cold blood as many of his own species, who have never offended him, as possibly he can.

Jonathan Swift (1667-1745) English writer and churchman

Gulliver’s Travels, Part 4 “Voyage to the Land of the Houyhnhnms,” ch. 5 (1726)
    (Source)

Following a long litany of the causes of wars in Europe, the number of such causes leading to the "trade of a soldier" being held "the most honourable of all others," for the above reason.