"The concept of the work is astrological rather than astronomical (which is why Earth is not included). The idea was suggested to Holst by Clifford Bax, who introduced him to astrology when the two were amongst a small group of English artists holidaying in Majorca in the spring of 1913; Holst became quite a devotee of the subject, and liked to cast friends' horoscopes for fun. Each movement is intended to convey ideas and emotions associated with the influence of the planets on the psyche, not the Roman deities. Holst also used Alan Leo's book 'What is a Horoscope?' as a springboard for his own ideas, as well as for the subtitles (i.e., 'The Bringer of...') for the movements."