In The Beginner’s Guide to Constructing the Universe, Michael S. Schneider points out that “one” and “two” were viewed by the ancient mathematical philosophers as the parents of numbers and therefore the number “three” would be the firstborn of the pair. Geometrically, three lines form the first object to have a measurable surface, the triangle. Linguistically, the sound of the word “three” resembles other words such as “through” and is clearly related to the word “threshold.” Schneider points out that three “takes us over a threshold and through past polarised limits of the Dyad.”
Our preference for release from the constructs of the dyad is reflected in our well known stories: “Goldilocks and the Three Bears,” the story of the Three Wise Men at Christmas time, “The Three Musketeers,” “Three Blind Mice,” “Three Men in a Boat,” the three witches in “Macbeth” and “Three Little Pigs.” Throughout history, we have naturally divided any whole into three parts, the beginning, middle and end or even past, present and future. There is a triple-headed goddess and the three phases of womanhood itself: virgin, mother and crone. In Christianity, there are three persons in the Godhead, Father, Son and Holy Ghost. We divide our day into morning, noon and night and take our meals to correspond with the sun’s three stages of dawn, noon and dusk. We tend to commence events by saying “On the count of three. . .” We give three cheers, make three wishes and say things are “as easy as one, two three.” Conversely, we also say bad things happen in threes and in baseball, three strikes mean you’re out.
Schneider notes that three implies strength. This is most easily observed in the arches found in buildings or even the arch formed by our legs (the keystone which would be our pelvis). A braid, made of three intertwined strands, is designed for strength. According to the Ojibwa tradition, to braid someone’s hair is to unite past, present and future. To destroy the universe, writes Schnieder, one has to use three way 120 degree joints because materials broken suddenly (as in an explosion) tend to break in triangles. Materials that have broken down more slowly over time make a four cornered pattern.
Three seems to be the basis of life forms as many vegetables (such as cucumbers, melons and peppers) contain a triangular structure when cross-sectioned. The bodies of insects have three sections and the human body begins life as a three part structure. The three primary colours, red, yellow and blue are found (in different ratios) in all colours.
Three turns a flat, two dimensional line into a shape: two opposites become balanced by a third element and become a completely different reality. Schneider writes that the scales of justice quite rightly represent the process of a trial. It is a simple balance reconciled by a third independent aspect.
Astrologically, since dividing the zodiacal circle into three makes a trine aspect, three is seen as generally favourable. A trine is a harmonic, flowing, positive astrological aspect. According to Robert Pelletier in his book Planets in Aspect, a trine “has the nature of the Sun and of Jupiter and the qualities contained in Leo and Sagittarius.” It is easy to see how a trine can be viewed as fortunate when one considers the positive qualities of the Sun (all planets revolve around it) and Jupiter which is often associated with luck or good fortune. Both the Sun and Jupiter and their respective signs of Leo and Sagittarius are associated with royalty. However, Pelletier implores the astrologer to view the trine aspect with reserved optimism. Since it is an “easy going” aspect, a trine lacks the strength to counteract more difficult aspects. A trine is meant to be enjoyed–and like nice weather, one tends to appreciate a trine only when more difficult aspects begin to play up and the trine aspect is no longer available to be appreciated. Trines are astrology’s fair weather friends.
Sometimes in a chart a planet is in a trine to another planet and the two are in trine to a third planet, making a 120 degree triangle. The three (sometimes more than three planets can be involved) form a complete triangle known as a “Grand Trine.” Typically, though not always, the planets involved in a grand trine will all be of the same element. One might think so many lucky angles would only enhance the native’s chance to be lucky in life. However, Pelletier notes grand trines are traditionally regarded as a difficult configuration because it “produces apathy and indifference to responsibility.” With the trines’ association with royalty and luck, perhaps a grand trine also produces the assumption that the native somehow expects good things to fall into their laps or perhaps even royal treatment. Pelletier also points out grand trines are often found in the charts of criminals. The writer has noticed the prominence of grand trines in the charts of serial killers Ian Brady, Jeffrey Dahmer, John Wayne Gacy, Edward Gein, Richard III and Beverly Allitt. Whilst an astrologer would be ill-advised to assume that all natives with a grand trine would have an indifference to law and order, it is worth noting that too much of a good thing is not always a positive.
The number three is embedded on our psyches because it is the basis of life. Schneider says “threeness shows that we’re not separate from the rest of the universe but are literally braided into it.” It seems almost inevitable–especially when one considers the Earth is the third rock from the sun.
 Schneider, Michael S., A Beginner’s Guide to Constructing the Universe, Harper Perennial, 1995, p. 39
 Story from author’s childhood
 Pelletier, Planets in Aspect, Whitford Press, 1974, p.177
 Schneider, Michael S., A Beginner’s Guide to Constructing the Universe, Harper Perennial, 1995, p. 59