Sentence:  Life is further characterized , in antithesis to Piepsam , as animal : the image of a dog , which appears at several places , is first given as the criterion of amiable , irrelevant interest aroused by life considered simply as a spectacle : a dog in a wagon is `` admirable '' , `` a pleasure to contemplate '' ; another wagon has no dog , and <WSD>therefore</WSD> is `` devoid of interest '' . 
Meaning of the word marked with <WSD> tags:  (used to introduce a logical conclusion) from that fact or reason or as a result