artlessness       
noun [ U ] uk/ˈɑːt.ləs.nəs/ us/ˈɑːrt.ləs.nəs/
 单纯,直率;无邪
the quality of being simple and not intending to deceive
  The beauty of children is in their innocent artlessness. 孩子的美在于他们的天真无邪。 
 To a first-time reader, the artlessness of her writing is a surprise. 她写作的直率风格会令初次阅读她作品的人感到吃惊。 
 See: artless
 - More examples
- She never abandons her spirit of apparent artlessness and naiveté.
- His summery jacket suggests artlessness and love of convenience.
- The short film is shot with surprising artlessness.