Graphology to use it for personality evaluation, empirical studies fail to show the validity claimed by its supporters. The word "graphology" is derived from "grapho-" (from the Greek γραφή, "writing") and "logos" (from the Greek λόγος, which relates to discussion or theory). Jean-Charles Gille-Maisani stated in 1991 that Juan Huarte de San Juan's 1575 "Examen de ingenios para las ciencias" was the first book on handwriting analysis. In American graphology, Camillo Baldi's "Trattato come da una lettera missiva si conoscano la natura e qualita dello scrittore" from 1622 is considered to be the first book. Around 1830 Jean-Hippolyte Michon became interested
What Love Is Made Of extremely positive about "What Love Is Made Of", describing it as "darker than anything" from "On a Mission", while calling it "slinky". The reviewer went on to commend the "irresistibly pouty" chorus. Pitchfork Media's Katherine St. Asaph commented that, in the song, the singer "sound[ed] completely enthralled, by either her lover or the music" and complimented her voice, noting that it seemed "ten times bigger than before". Jordan Sargent of "Spin" magazine called the track "exuberant" and highlighted Katy's vocal performance, which he deemed "typically fantastic", while the team from pop music website Popjustice gave "What Love Is Made Of"