Diurnal means ‘of the quality of the day’;
nocturnal means ‘of the quality of the night’. Diurnal energies relate to
masculinity and the solar principle, being active, direct and expressive,
whilst nocturnal energies relate to femininity and the lunar principle, being
responsive, indirect, and impressive. Yin and Yang are analogous oriental
terms. The characteristics of diurnal and nocturnal influences infiltrate many
areas of astrological philosophy, from the alternation of the signs (usually
referred to as masculine and feminine), to the assignation of planetary
rulerships over the signs. Apart from the Sun and Moon each planet has two
rulerships – one diurnal, one nocturnal – to recognise their expression in
these altered states (for example, Mars rules Aries, its diurnal ‘house’, and
Scorpio, its nocturnal ‘house’).