How can the figure of Mr. Tulliver be described as tragic in The Mill on the Floss?

Several factors contribute to the idea in the reader's mind of Mr. Tulliver as a tragic character, although Mr. Tulliver is not an example of a classic one.  Classically "tragedy" means "representations of serious actions which eventuate in a disastrous conclusion from the protagonist (the chief character) (331.)  First, it can be argued that Mr. Tulliver is not the protaganist of the novel (that is probably Maggie.)  This is not classical drama, however, and long novels like Eliot's usually have more than one main character, and Mr. Tulliver is certainly a major actor in the first five books of the novel.  Secondly, many of Mr. Tulliver's actions are more humorous than they are "serious".  Tulliver is continously argumentative with his neighbors, and is actually somewhat of a caricature of a petty English landholder of the time:  litigious, contentious, prideful, and self-important.    Also, compared to classical tragedy, the death of Mr. Tulliver is not disaster for everyone around him.  It is certainly sad, but it does not completely destroy the lives of the rest of the characters (as the death of Antigone does, in the play of the same name.)  Also, Mr. Tulliver did experience some joy before his death.  His son was able to pay off his debts, and Mr. Tulliver knew of this before he died.  He also soundly thrashed Lawyer Wakem, his archenemy, before his death.  So Mr. Tulliver was not completely tragic; he is certainly humanly tragic, but he did experience both success and failure in his life, as most people do.

So in what way is Mr. Tulliver tragic?  Most tragic characters have a tragic flaw.  There are a few different types, but mostly they are overarching, typically human failings such as hubris (pride), blindness of one sort or another, or failures of judgment.  Mr. Tulliver's major flaw (and he has more than one, certainly) is his lack of introspection and self-knowledge.  Tulliver married his wife because of her lack of intelligence.  While this was certainly a funny (and ironic) social commentary on small landholders during the Victorian age, it also hampered him.  Mrs. Tulliver, though from a wealthy family, is unable, through her stupidity and lack of character, to cajole or compel her wealthy relatives into helping the Tullivers when they most need it.  Tulliver also has an unalterable grudge against Wakem, which, had it been mitigated by him in some way, might have lead to better circumstances for himself and his family after the mill was sold to him.  Tulliver certainly dies in a tragic way, before he can enjoy the return of the mill to his family, but so many of his failings are brought on by either his obstinancy or his blindness that it is difficult to see him as completely "tragic".  He is, more correctly, a realistically human character, with more recognizable human contradictions, and his share of the usual human foibles and failings.  

This does not mean that the death of Mr. Tulliver causes less emotional impact on the reader than a classically "tragic" character's death would.  On the contrary, Eliot's depiction of such a realistic, believable, authentically human character as Tulliver, mostly causing his own demise, rings true in the reader.  Therefore, Tulliver's fate is all the more affecting. 

Source: Abrams, M. H. A Glossary of Literary Terms.  Boston: Thomson Wadsworth, 2005.