A school of astrology known as cosmobiology arose in the 20th century in Germany. This school focused on the use of midpoints, and de-emphasized signs and houses to the point that they were used little by some practitioners, and not at all by others.
There has never, though, been a school of astrology that did not use planets, because planets are the most essential, most indispensible part of astrology. The planets MOVE and create CHANGE. The houses and signs, by comparison, are static. They do not move in relationship to each other. They are the receptacles for the energy of the planets.
Each planet, except for two of them has a polar opposite, and one of the best ways to study astrology is to know these polar opposite pairs, to contrast them with each other, and to always think of their energy as being in dynamic balance to each other. Here is a list of the pairs. I have designated a yin or feminine component, abnd a yang, or masculine component in each pair:
Sun (yang) and Moon (yin)
Mars (yang) and Venus (yin)
Jupiter (yang) and Saturn (yin)
Uranus (yang) and Neptune (yin)
Mercury and Pluto are not a pair — each one standS alone. Pluto has no energy of its own — it takes on and intensifies the energy of whatever it comes in contact with. Mercury is a connecting energy, flexible, both masculine and feminine.
Marc Jones designates the Sun/Moon pair as signifying VITALITY, THE Mars/Venus pair as signifying EFFICIENCY, the Jupiter/Saturn pair as signifying MOTIVATION, and the Uranus/Neptune pair as signifying SIGNIFICANCE.
In a later posting I will talk further about the meaning of each one of these pairs as well as the meaning of various aspects between them.