The subtitle of the novel, A Pure Woman Faithfully Presented, leads us to the heart of Hardy's intention. "Faithfully Presented" speaks to Hardy's naturalism: the phrase tells us that, in this book, events will unfold in a universe indifferent to the fate of human begins. Therefore, there will be no contrived happy ending in which Tess's pure heart is rewarded by a beneficent providence, for there is no good God meting out justice in Hardy's worldview.
However—and this is key—Hardy wants us to understand that Tess is "pure." What happened to her—her rape, impregnation, and abandonment—was not her fault. She was more sinned against than sinning. The universe may be indifferent, but Hardy takes aim straight at a society which is capable of change but nevertheless blames the victim and makes life as difficult as possible for a girl like Tess. She is "ruined" and "soiled" when still a teenager because she is innocent and naive, just as a young girl is supposed to be in Victorian culture.
Tess pays to the "uttermost farthing" for being a woman in a society that allows women no leeway for transgressing against its moral code but adheres to a double standard that allow men to be sexually promiscuous while savagely punishing women for the consequences of these acts.
The sentence, "Tess is more sinned against than sinner," has much to do with the presence of Fate in Thomas Hardy's Tess of the d'Ubervilles. Chance and Fate are ever-present throughout the story because no matter how hard Tess tries to make the right choice, or to do the right thing, Fate had a way of throwing insurmountable obstacles at her that caused pain, loneliness, and suffering. The first sentence in the last paragraph of the book validates Fate's presence by saying, "'Justice' was done, and the President of the Immortals, . . . had ended its sport with Tess" (enotes.com, eText, pg. 249). It seems so frustrating for Tess that throughout the whole story, she is plagued with an extreme situations;such as becoming a teenage mom during a very unforgiving Christian period like that of the Victorian Age. Other times when Tess is more of a victim than a sinner is when her mother guilts her into meeting Alec d'Uberville and she is seduced, when Alec doesn't first ask him to marry her before he sleeps with her, and when she is dealt with unfairly by Angel and driven to madness and murder because of it. If she had known how to be a more confident and independent woman rather than a pitiful victim, she would have made more choices that would have been for her own benefit and not for the appeasement of others.