1. Sole as in "the bottom of a shoe or foot":
* Soleness: This refers to the state of being a sole, the bottom part of something. This is a less common word.
* Base: This is a more general term for the bottom or foundation of something.
* Foundation: This emphasizes the structural support of the bottom.
2. Sole as in "only":
* Exclusivity: This refers to the state of being the only one, or being exclusive.
* Singularity: This emphasizes the uniqueness of being the only one.
* Solitude: This emphasizes the state of being alone or isolated.
You would choose the appropriate abstract noun based on the specific meaning of "sole" in your sentence.