Generally it’s established that the 1st house is ruled by Aries and Mars. It is the house of the Ascendant, our immediate identity in the world, and what we want to experience.
This house will show what drives a person to live their life.
The sign here indicates the ideas we have that give us motivation to move forward, to start new experimental projects, and trying new things. This shows the types of experiences that we want to have, in our own lives.
For example: Someone with Sagittarius on the Ascendant has ideas of philosophy and absorbing information, sharing knowledge and insights all around them. Travel and seeing all different aspects of life, seeing the bigger picture of what makes life, life itself.
The house of the ruling planet will tell the areas of life we express these ideas as our pursuit to our individuality of going where we want without being told by anyone else.
For example: Sagittarius Ascendant is ruled by Jupiter….if Jupiter is in the 10th house then this Ascendant would love to be in experiences where they are looked up to for their beliefs, so that others can seek some kind of guidance or teaching from them.
It is the house where we make our own decisions about what life means to us, and what we choose to do with it.
When there are planets in the 1st house/Ascendant house, it shows the tactics we use to initiate the types of projects we are interested in. The planets also influence the sign to make the interests in life pointed into similar areas of the ruling planet.
For example: Someone with Pluto in the first house may have this sexy, magnetic attraction about them, not only(if) because they flash their sexuality, but because they are good at bringing life experiences to them. They want what they want, and they will use their ability to seduce to be exactly where they want to be without anyone’s help. This Pluto energy makes the person intense because it is as if they can literally have life in the palm of their hands.
And if Pluto is here with Sagittarius on the Ascendant, then this would make the Sagittarius person crave experiences that are occult, that most people are afraid to tread. So let’s say Sagittarius already wants to learn everything there is to know, and if Pluto is here, then maybe they want to know more about ghostd, haunted parts of the world and they travel there to experience those haunted places. Then they can say they lived to share those experiences.
Look to aspects to the Ascendant for similar descriptions for having planets in the house itself, to understand how you go about obtaining the things you want out of life.
Look to aspects to the ruling planet to see how you are able to stay motivated to achieve your desires and to go after them, your source of motivation.
Celestial Insight 