Mencken admired the German philosopher Friedrich Nietzsche (he was the first writer to provide a scholarly analysis in English of Nietzsche's views and writings) and Joseph Conrad. His humor and satire owed much to Ambrose Bierce and Mark Twain. He did much to defend Dreiser despite freely admitting his faults, including stating forthrightly that Dreiser often wrote badly and was a gullible man. Mencken also expressed his appreciation for William Graham Sumner in a 1941 collection of Sumner's essays and regretted never having known Sumner personally. In contrast, Mencken was scathing in his criticism of the German philosopher Hans Vaihinger, whom he described as "an extremely dull author" and whose famous book "Philosophy of 'As If he dismissed as an unimportant "foot-note to all existing systems."