The Four Elements

The Polarities

Masculine - Aries, Leo, Sagittarius, Libra, Aquarius, Gemini
The masculine signs, also called positive, are the extrovert of the zodiac. This shouldn't be confused with having an excessive amount of testosterone. Think of it as Yang energy, in the active pole.
Feminine - Capricorn, Taurus, Virgo, Cancer, Scorpio, Pisces
The feminine signs, also referred to as negative, are naturally introverted. And again, this has nothing to do with gender as we recognize it.
The "beefiest" sign of the zodiac, Taurus, is a feminine sign. This can also be thought of as Yin, symbolizing receptive energy.
Not only do Elements affect compatibility (on a very basic level) in that Fire and Air signs complement each other while Earth and Water signs are mutually supportive, but there are also some natural affinities around the chart wheel as well.
Each sign has a special relationship with the sign opposite it

These are the four elements of the zodiac

Earth

Earth signs: Taurus, Virgo, Capricorn
Earth and the Physical
The element of earth is embodied in the physical substance of the mountains, the soil, and the life that springs from the soil. In mountains we see the stability and solidity of earth. Soil provides nourishment and vegetation sustains life.
Earth is the cradle of all the other elements. From the earth we draw the materials on which our society is based. Our food and shelter is reliant on the earth, as is our ability to carry water, to contain fire and to move with air.
Our monetary system is a symbolic representation of gold and the material possessions we can buy. The cycles of earth are dependable and predictable, which allow us to live structured, ordered lives.
Earth creates and nurtures life, much like our bodies are able to do. The creativity of earth is very productive and useful.
The materially creative are able to see the potential of an object and craft it according to their design. In doing this they use the five senses that allow us to experience the physical world.
"Sensing" is the Jungian term inspired by earth. Earthy personalities are found in the astrology signs Taurus, Virgo and Capricorn.

Water

 

Water signs: Cancer, Scorpio, Pisces
Water and the Emotions
The fluidity of water describes our emotions. The turbulent sea has inspired many poets; water is, in fact, the element of the poet.
The surface of the sea erupts into waves that can be gentle and slow or unpredictable and life-threatening. Deeper than the surface of the sea are quiet calm and a plethora of interesting, colourful life-forms.
Water represents the subconscious mind. Comparing the human mind to the sea, that world in the deep waters is our subconscious, filled with creatures we can only glimpse briefly. The imagery of the subconscious is likened to the imagery of the poet, with symbols holding deeper meanings that effect us on an emotional level.
The watery womb is nurturing and life-sustaining. Going "back into the womb" is a phrase that implies comfort and security.
The womb also reflects the creative qualities of water. The watery individual is able to develop a creative project over time.
The water signs in astrology are Cancer, Scorpio and Pisces. Jung used the concept of water as inspiration for his "Feelings" category of human psychology.

Air

Air signs: Gemini, Libra, Aquarius
Air and the Intellect
Air symbolizes thought. Thought is a continually present force in our lives, as inescapable as the air we breathe. In order to think clearly, it is necessary to be calm and focused.
Deep breathing is a common method in meditation because of its ability to induce peace. The manner in which we breathe is so influential over our mental state that the yogis of India have developed different styles of breathing to induce varying levels of energy and relaxation.
Humanity has found a use for air in many of our greatest inventions. Electricity was discovered following a lightning storm; for transport we use air to propel a sailboat and to keep a plane aloft.
This ability to use something for a new purpose is one of the defining acts of intellectual genius.
In Jungian psychology, the element of air was transformed into the concept "Thinking". Air is linked to the suit of Swords in the tarot deck.
In astrology, the signs that are influenced by air include Gemini, Libra, and Aquarius.

Fire

Fire signs: Aries, Leo, Sagittarius
Fire and Intuition
Human beings initially knew fire primarily as a means of destruction. When we learned to control fire and harness its energy, our civilization began to make rapid advances. This dual nature of fire as both a destructive and a creative force harnessed the spirit of our intuition.
The occasional forest fire is a benefit to the natural world. The rich soil nourished by the ashes allow for abundant growth.
In our lives we can relate fire to the removal of useless or destructive habits and the subsequent creation of a stronger self.
But it is for its qualities of heat and light that fire is most often used. The light of our intuition allows us to explore undiscovered areas.
When we get an idea in a sudden flash of insight, this is our intuition at work. The heat of our intuition gives us our energy. Our primal nature gives us our instinctual drive to reproduce, create and expand.
Jung referred to the energy of fire as "Intuiting". The qualities of fire are seen in the psychological profiles of the astrology signs Aries, Leo, and Sagittarius.