The larger theme about Humanity Thomas Hardy is trying to convey to the reader is that after you die no one remember or cares about you. The idea is that you are no longer on the earth and have no ability to make people remember you.
The author shows this theme with many examples durring the poem. One example is when the persona asks if it is her enemy digging on her grave. Her dog replies "She thought you no more worth her hate, And cares not where you lie." This shows that not even the person's enemy bothers to remember how much he or she hated the persona. The persona's enemy has no desire to think about her now that she is dead, the enemy doesn't think it is worth his or her's time.
Another example convaying this theme would be the dog's response to the persona asking if her husband was the one digging. The dog says "No: yesterday he went to wed One of the brightest wealth has bred." This qoute tells the persona, the one who died, that after she had died her husband immeadiatly remarried some wealthy women. He forgot all about his previous wife and moved on. It says they married the next day which would imply that the persona's husband forgot about his dead spouse rather quickly after her death.
A final example of the theme in the poem would be the qoute from the dog after their owner asked if it was them digging on her grave. The dog said "I'm sorry, but I quite forgot It was your resting place." This could mean a few things. One would be that the dog has net even bothered to remember where his owner as burried after her death. It could also mean that the dog has totally forgotten about his diseased owner and not cared to remind themself about her. The last possible idea about this qoute could be that no one cared enough to get any sort of marker that showed that she was burried her. Someone didn't even bother getting a tombstone to mark her grave. This could of made the dog not forget if something like this was there.
The theme Thomas Hardy is trying to convey about humanity to the reader is shown throughout the poem. Thomas Hardy uses different lines of dialect to set these examples up, but they all share a common theme.