simpleness(property of being simple) noun [UK: ˈsɪmplnəs ] [US: ˈsɪmpəlnəs ]
simplicity [simplicities](quality or state of being simple, unmixed, or uncompounded; as, the simplicity of metals or of earths) noun [UK: sɪm.ˈplɪ.sɪ.ti] [US: ˌsɪm.ˈplɪ.sə.ti]Simplicity is the key. = La simplicidad es la clave.