The state or quality of being wishful; sometimes specifically wishful thinking(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "wishfulness" in a sentence
"I guess it was said more in wishfulness than in truth."
"With Germany reeling from Alamein and Stalingrad, it was prone to that "wishfulness" and "yesmanship" that are the cardinal sins of counter-deception."
"The Chilcot inquiry has amply demonstrated the role of "wishfulness" and "yesmanship" in the decision to go to war."