The Collaborative International Dictionary of English v.0.48:
Ideality \I`de*al"i*ty\, n.; pl. Idealities. 1. The quality or state of being ideal. [1913 Webster] 2. The capacity to form ideals of beauty or perfection. [1913 Webster] 3. (Phren.) The conceptive faculty. [1913 Webster]WordNet (r) 3.0 (2006):
ideality n 1: the quality of being ideal