The first astrological house signifies IDENTITY -- this is the keyword that the famous astrologer Marc Edmund Jones gave to it.
What is the nature of identity? Seen in spiritual terms, it's an illusion -- our means of manifesting in the realm of phenomena. The difference between a healthy identity and a pathological identity is that when healthy our identity is flexible, that is, capable of change, and is an instrument and vehicle for the expression of the Light of Pure Consciousness, a lens focusing that light in the physical world. A pathological identity is something we cling to obsessively and addictively, needing desperately to convince ourselves and others that we are someone special as a compensation for deep feelings of worthlessness.
Identity is a mask, but one we have to wear as long as we are living in the realm of relativity. The question is, does our mask express the energy of our divine self, or are we so caught up in the illusion of it that it divides our consciousness from our core?
Any planet in the first house bears the stamp of our uniqueness. A person with Mercury in the first house, for instance, has their own unique way of expressing ideas. They identify themselves as communicators and thinkers, and also as a go-between or messenger -- a facilitator.
What we most need, when it comes to dealing with planets in the first house is not to become to attached to them, that is, over-identified with their functioning. I have Mars in the first house. My uniqueness comes out in what I do, and how I assert myself (Mars). But I need to be careful not to overidentify with what I do. I AM NOT WHAT I DO.
It is very important to realize that the first house signifies the most superficial aspect of our being, just as our current identity is only the outward manifestation we are currently wearing.
The first house is our surface. Many people reject it for this reason. "I am not a surface person," they think, "I am a deep and sincere person." The problem is that the surface is what others see of us, especially in their initial encounters with us, and so our surface/identity is really a means of communication. It can either reflect who we are inside, or it can hide our true self. What we ultimately need is to form our identity in such a way that it works for us as we navigate through live, rather than thwarting us in what we are trying to do.
Example: With my Mars in first house, I can come across to others as aggressive, sometimes provocative. I have had people say they were initially turned off by me because of that. Then when they got to know me, they saw that my aggressiveness was due to my having a passionate nature, and that I had many other qualities other than the surface aggressiveness that they initially saw.
So the first house is easily misread as being the whole of the person, when really its only a surface to which people readily stick labels. With Mercury in the first house a person may seem flexible, or maybe flighty or fickle. But this is an appearance, and not necessarily a reality.
One of the most difficult planets to have in the first house is the Moon, for the Moon is receptive and vulnerable. Moon in the first house tends to form their identity around who others want them to be -- they are very receptive to the needs of others and of adopting the identity that is expected of them. My advice to them: choose your companions, friends, and long-term partners carefully, for you are a mirror and they will shine their energies into you. Think of them as food you are taking in. Are they nourishing for you, or poisonous to you?
Also, the Moon is always where we tend to have perceptions that are distorted by feelings. Moon in first house may identify with something one day, and then the next day identify with something different, depending on their mood.
You may also think of any planet in the first house as the role you will tend to play in life. I am SOMEONE WHO GETS THINGS DONE, AN ACTIVATOR (MARS). Venus in first house plays the role of PEACEMAKER, ARTISAN, OR EASY-GOING GUY -- OR MS. ALLUREMENT. Jupiter is THE ENTHUSIASTIC ONE -- ALWAYS UP, ALWAYS SEEMING TO BE FULL OF POSITIVE MOTIVATION. It can be a problem if a Jupiter in first house person becomes depressed, because their depression will have this seemingly optimistic overlay -- people may have a hard time believing they are really depressed.
Saturn in first house can come across as critical, cold, rigid, or overly serious, when maybe they really aren't this way, or at least are not meaning to appear to be this way. Saturn here can be frustrated about who they are, or how they look, or about any aspect of themself. They need to learn to be patient with themselves and to let go of negative attitudes about their appearance, as well as how others react to them. They need to become aware of the negative things they are identifying with, and work diligently to unhook themselves from those limiting and negative self-concepts which they have built.
Saturn simply will not stand for anything less than complete alignment with spirit. The Saturn in first house's road to true happiness is to stay at the center of the truth that they are a spiritual being, and that the life they are living is for the purpose of spiritual growth.
Pluto in first house can be difficult. The person cannot exist in a state of stasis -- there is always a feeling that they must be growing and transforming. Any identity they try to take on can feel limiting, restrictive, and unreal. They can become over-identified with whatever role they adopt in life, but will always feel compelled to untimately GO BEYOND any identity they take on. Also, others may place heavy expectations on them, for Pluto is PRESSURE, and although they may experience this pressure as coming from outside themselves, its true source is always FROM WITHIN.
So those are some thoughts on the first house for right now. May all your masks help you to joyfully play your role, and be easy to take off -- when the time comes.