Mortality Quotes in Harry Potter and the Half-Blood Prince

How we cite our quotes: (chapter.paragraph)

Quote #10

"But firstly, no, Harry, not seven Horcruxes: six. The seventh part of his soul, however maimed, resides inside his regenerated body. That was the part of him that lived a spectral existence for so many years during his exile; without that, he has no self at all. That seventh piece of soul will be the last that anybody wishing to kill Lord Voldemort must attack – the piece that lives in his body." (23.98)

We wonder what this soul must be like. What does a soul look like? What does it do? What does it provide a person? If Voldemort operates with only a seventh of his soul within his body, what must he be like? Can he be happy, or do you think he cares about happiness?