The definition of “ghost, n” in Ambrose Bierce’s puckish “Devil’s Dictionary” is “the outward and visible sign of an inward fear,” and although Bierce was not an entirely reliable lexicographer, his authority on this subject is beyond question. He knew more than any man should about both inward fears and their outward and visible signs. And he was at least arguably the most powerful American writer of horror fiction between Poe and Lovecraft. (Henry James’s supernatural tales are in a class by themselves.) In his career Bierce wrote more than 40 spooky stories, most of them about ghosts, along with a fair number of short narratives — some true, some fanciful — about the horrors of war. All his tales, both the ones about soldiers and the ones about the haunted and the haunting, are steeped in loneliness and dread, which he evokes with the precision of someone familiar with their every nuance. A fat new Library of America volume, Ambrose Bierce: The Devil’s Dictionary, Tales, and Memoirs ($35), collects the best of his work, and almost every page has something to give you the chills, though not always, perhaps, in the way the author intended.