One way of answering this question would be to analyse the subtitle that Hardy chose for this excellent novel. Let us remember that this "Story of a Man of Character," which immediately makes us think of the way in which this novel focuses on the importance of character and how the traits of a character determine his or her fate. The focus on the term "character" raises a number of interesting questions, such as the way in which honour and moral righteousness relates to character.
Henchard as the protagonist of this novel does not seem to fit any neat description of character. He is subject to violent outbursts of emotion whilst at the same time becoming engaged in a inexorable competition with Farfrae that destroys him as a character. His defects and insecurities result in him lying to the only other character in the novel that he truly loves, Elizabeth-Jane. The way in which Henchard dies, alone, and desires to be forgotten, seems to plunge him into obscurity. There will be nothing to remember him and what he achieved in life.
However, at the same time, Hardy states that in spite of this rather unpromising life, he is a man who is worthy of remembrance. The qualities that make him this "man of character" are the way that he faces up to his failures and the pain and suffering that he brings upon his own shoulders. For Hardy, who believed in a world where there was some Immanent will out there determined on frustrating the lives of the humans in it, being a man of character is determined by how we endure such "schemes" as we face the capricious and uncaring nature of the universe. This makes Henchard a character full of honour. The purpose for writing this novel therefore seems to be to discuss what makes a "man of character," and to suggest that what we think of as making a "character" might not necessarily be accurate.