Why are there only 12 houses in a chart? And who decides House matters?

Most astrological texts that I have come across start off with the 12 signs and 12 houses as a ‘given’ and students then learn how to construct these charts and give readings with them. I am not sure whether anyone has wondered why there are only 12 houses or 12 signs. Why is the cosmos not divided into 11 or 13 or even 24? Another question that I have hardly heard asked, is why does x House denote so-and-so matters?

While I am sure there are many explanations out there, I am going to give my understanding of why a chart would be divided into 12 parts and not 11 or 13. I will also attempt to demonstrate why certain houses are considered for certain aspects of human existence. I am not an astrophysicist or a rationalist, so I will be flexible in my views if I am wrong and encourage readers to write here or email me with their insights.

For understanding the 12 divisions of the chart it is necessary to take a quick look at the concept of platonic solids. A platonic solid is a three dimensional figure/ shape whose each side exactly resembles every other side. 

The name comes from Plato who is supposed to have believed that nature could be described in five shapes. The five shapes are believed to have been in existence long before but it was Plato (in recorded Western thought) that first tried to link the shapes to the material world. Only five platonic solids are mathematically possible, and perhaps this is the reason that Plato thought of linking it to the five building blocks of the material world.

Hindus reading this will be well versed with the five elements: Fire, Earth, Air, Water, Space. However, most of us seem to think Earth is the physical earth below them and air is the air that we breathe. This is not the correct understanding. By Earth, it was solids that were being referred to, by Water: liquids, by Air: gaseous and Fire is that energy that sits in and in between these elements acting as a conversion mechanism. And space? Well space is the vessel/ area in which these elements and their inter-conversion can occur.

Source: Frank Wilczek, pbs.org

While why Plato decided upon a dodecahedral representation of the universe is a study for another time, it is interesting to note that scientists have indeed examined this issue. In fact, an award winning mathematician Jeffery Weeks collaborated with French cosmologists in studying cosmic background radiation observed by NASA's Wilkinson Microwave Anisotropy Probe (WMAP) and hinted at a possible answer:

“The universe is finite and bears a rough resemblance to a soccer ball or, more accurately, a dodecahedron, a 12-sided volume bounded by pentagons”

As such, this student surmises that it is using the dodecahedral representation of space that the chart is divided into 12 parts. It has nothing to do with the signs as visible in the sky, so the discovery of the 13th or 14th sign will not impact the manner in which a chart is divided. 

Now coming to the second question as to why a certain house is considered for a certain matter. For that I will have to postulate a theory and then see if it fits or not. The significance of 4 houses in a chart is symbolically very strong. These are the houses 1, 4, 7, and 10. It is no wonder then that these houses are known as kendras or cardinal houses. The meaning of the word cardinal is ‘fundamental’. As such, these four houses are the rock solid foundation on which the chart significations are built. 

Each of these cardinal houses impact one house ahead of them and one house behind them. So, the 1st house (Ascendant) will impact the 2nd house and the 12th house. The 4th house will impact the 3rd house and the 5th house. The 10th will impact the 9th and 11th and 7th will impact the 6th and 8th. The rules to interpreting these impacted houses remain similar, the house before is negative to the house and the one after is positive to the house. While this is similar to what some schools of astrology teach, it differs in that while 2nd house will add to Asc and 12th will deduct from Asc, 2nd will not deduct from the 3th and 12th will not add to the 11th (how does house of loss add to the house of gain anyway?!). In this, I differ with the adage that “EVERY house destroys the significance of the house ahead of it and adds to the house behind it”. 

 Lets take an example of 4th house. The 4th house is that house which physically exists on the other side of the planet earth from the place where the native is born. In other words, it is buried deep below. It is this attribute that gives the 4th house its controlled aspects in the life of the native. The native lies buried deep within his mother’s womb. As such the 4th house represents the mother. The ‘buried deep within’ also translates to secrets. Most people divulge secrets to their mother.  Mother also means mother land, i.e. the place which the native considers home. So it includes house property and things allied to it. The first lesson a child learns is from his mother, so it is also the house of education. 

Now how does the 4th house impact the 5th house? As discussed earlier, the 5th house adds to the 4th house. If 4th was the house of a parent (mother), the 5th is house of the child of a native. If 4th house was the house of receiving love (from mother), then 5th is the house of giving love (either to child or romantically to a partner). If 4th house gave education, 5th house is intelligence. If 4th represented motherland then 5th will give connections to foreign lands. If 4th is curricular, 5th adds extra-curricular (hence entertainment, sports, etc)

How does the 4th house impact the 3rd house? If 4th house signified home, mother, etc. the 3rd signifies staying away from home. To stay away from comfort requires courage. Thus the 3rd house is the house of courage. Since 4th house is the house of secrets, the 3rd house becomes the house of communication. 4th house represents mother, so 3rd house will represent things that take mother’s attention away from him…siblings. 

This way we can see how the 4th house’s significations make symbolic sense and using these significations how one derived the significations of the 5th and 3rd.

We can take the example of the 10th house, another cardinal house. The 10th house is the topmost point in the sky above the native at the moment of his birth. Thus if 4th was the secret, then 10th will be how the native will behave in the world outside. It is the opposite of the 4th house. As such the 10th will govern the native’s professional achievements, the natives mark on the world, authority, fame, promotions. 

Now how does the 10th house impact the 11th house? If 10th showed the natives hard work, the 11th will show the gains, the results of the 10th house. 

Now how does the 10th house impact the 9th house? The 9th house shows higher education, like PhD etc. People leave work to pursue higher education like PhD or MBA. Even if they do a part time course, the studies encroach upon their work impacting the quantity or quality. If 10th shows work done for worldly achievement, 9th shows work done for spiritual achievement, like pilgrimages. 

Thus a student can use symbolical references to derive the meaning of the cardinal houses and then use the positive and negative impact of the cardinal houses to derive the significations of all the 12 houses in a chart.  Why a house impacts the next house positively and negatively impacts the house before it is something that I do not have an answer for, yet. I will be working on the question though. Readers do write to tell me of your discoveries. Learning is after all a collaborative process.