The Sun is usually thought to represent the conscious ego, the self and its expression, personal power, pride and authority, leadership qualities and the principles of creativity, spontaneity, health and vitality, the sum of which is named the "life force".
The Moon is associated with a person's emotional make-up, unconscious habits, rhythms, memories, moods and their ability to react and adapt to those around them. It is also associated with the mother, maternal instincts or the urge to nurture, the home, the need for security and the past, especially early experiences and childhood.
Mercury represents the principles of communication, mentality, thinking patterns, rationality and reasoning and adaptability and variability. Mercury governs schooling and education, the immediate environment of neighbors, siblings and cousins, transport over short distances, messages and forms of communication such as post, email and telephone, newspapers, journalism and writing, information gathering skills and physical dexterity.
Venus is associated with the principles of harmony, beauty, balance, feelings and affections and the urge to sympathize and unite with others. It is involved with the desire for pleasure, comfort and ease. It governs romantic relations, marriage and business partnerships, sex (the origin of the words 'venery' and 'venereal'), the arts, fashion and social life.
Mars is associated with confidence and self assertion, aggression, sexuality, energy, strength, ambition and impulsiveness. Mars governs sports, competitions and physical activities in general.
Jupiter is associated with the principles of growth, expansion, prosperity, and good fortune. Jupiter governs long distance and foreign travel, higher education, religion, and the law. It is also associated with the urge for freedom and exploration, humanitarian and protecting roles, and with gambling and merrymaking.
Saturn is associated with the principles of limitation, restrictions, boundaries, practicality and reality, crystallizing, and structures. Saturn governs ambition, career, authority and hierarchy, and conforming social structures. It concerns a person's sense of duty, discipline and responsibility, and their physical and emotional endurance during hardships. Saturn is also considered to represent the part of a person concerned with long-term planning. The Return of Saturn is said to mark significant events in each person's life.
Astrologically modern interpretations associate Uranus with the principles of genius, individuality, new and unconventional ideas, discoveries, electricity, inventions, and the beginnings of the industrial revolution. Uranus governs societies, clubs, and any group dedicated to humanitarian or progressive ideals. Uranus, the planet of sudden and unexpected changes, rules freedom and originality. In society, it rules radical ideas and people, as well as revolutionary events that upset established structures. Uranus, among all planets, most governs genius.
Astrologically, modern Western astrologers associate the planet Neptune with creativity, idealism and compassion, but also with illusion, confusion, and deception. Neptune governs hospitals, prisons, mental institutions, and any other place, such as a monastery, that involves a retreat from society. Its appearance coincided with the discovery of anesthetics and hypnotism.
Astrologically, Pluto is called "the great renewer", and is considered to represent the part of a person that destroys in order to renew, through bringing buried, but intense needs and drives to the surface, and expressing them, even at the expense of the existing order. A commonly used keyword for Pluto is "transformation". It is associated with power and personal mastery, and the need to co-operate and share with another, if each is not to be destroyed. Pluto governs big business and wealth, mining, surgery and detective work, and any enterprise that involves digging under the surface to bring the truth to light. Pluto is also associated with extreme power and corruption.