If we look at the Zodiac as a progression of the soul from a feeling of being a totally separate entity evolving to feeling or “knowing” that we are all one (Pisces), then the start of that journey is Aries. Libra is the halfway point where we begin to be concerned about our “significant other.” This is the polarity of relationships. Aries is “I or me” and Libra is “you.” (Remember that people are ALL combinations of many signs, and it is impossible to find a pure example of any one archetype.)
Commonly, Aries is described as selfish or self-centered. That is a perception based on observation, perhaps, but is not entirely accurate. Many Aries people have important planets in nearby Pisces or Taurus and can be as compassionate as any other person—if not more so. Aries is “self-referencing” and self-reliant. By that I mean they measure everything by their own experiences or imagined experiences by seeing themselves in someone else’s circumstances. For instance, upon seeing a strange hair-do for the first time, their immediate thought is “How would I look in that?” In this way, Aries is a breath of fresh air because the first thought is not to criticize, but to imagine him or herself in the same condition. But, this self-referencing also makes it hard to see another’s viewpoint if they cannot put themselves in their experience.
Aries is the child of the zodiac and often retains an innocent attitude throughout life mainly because it is a sign that lives in the moment. They are neither innately deceptive nor vindictive (although there can be other things in a specific chart that provides those traits), but there can be temper tantrums due to frustrations of the moment. Aries people forget about the past rather quickly and don’t spend a lot of time worrying about the future, much like a child does. For that reason, they are often admired for being able to start all over again any number of times without dwelling on failures. Also, they are self-starters and prefer to do things by themselves without relying on others at all. More than any other sign, this one is more likely to be a sole proprietor, if self-employed, and often remains single without any discomfort or regret. They see themselves as completely separate from others and feel the right to be who they are without any interference. They would probably leave a marriage in which the partner tried to control them, since the primary need of these people is self-expression on their own terms. That is why it is easy for them to be pioneers (another key word of the sign) which can often be a lonely role.
Libra is the extreme opposite. This is the partnership sign. My teacher said once that Librans don’t leave a relationship until they have found a new one to replace it. The need to belong with a partner is so strong that Librans often actually look to others for their identity. The need is not only to connect to one other, but also to belong in society. It is the most uniformed of all the signs… “I’m wearing a Navy uniform, so I BELONG to that service and my identity is a sailor.” For this reason, also, Librans have a very hard time making a decision, since they do not want to make a mistake and therefore be “alone” or to offend. The Achilles Heel in this is the problem with wanting to fit in so badly, that conformity can take over. Having to have the “right” fashions, house, car, etc. can become all-consuming.
This is the halfway point of the zodiac where the soul’s attention goes from self to others. From Aries through Virgo, the soul is building a self… [my body/self (Aries), my possessions (Taurus), my thoughts (Gemini), my family/clan (Cancer), my creations/talents (Leo), my work/skills (Virgo)] but from now on, the soul is noticing that there are others out there not of our clan (actually others of the larger “one” we are part of). When we come to Libra, we feel uncomfortable if we do not have an “other” to complete us. But we are usually born into this sign unskilled at union with another, so we do what we believe we have to do in order to be acceptable. Usually, what happens is we lose ourselves in trying so hard to please the “other.” This, however, is also the sign of compromise and negotiation. What happens when we cannot do that? War. Libra is also the war sign as well as peace. It is simply getting along with others one-on-one without either one losing their individuality, either. That's why its symbol is the scales of justice.
This brings me to another cliché that drives me nuts. When I get students taking my correspondence course, they come conditioned by other things they’ve read, and often in exams I give, they’ll use those bits of knowledge to answer my questions, not remembering where they got that information. One is to refer to Librans as “seeking balance.” This is from the symbology of the scales. That is the most simplistic of all interpretations and I usually ask the student what that means. The scales symbolize justice, fairness, or in other words, the ability to retain one’s SELF while also relating fairly with another person. The scale symbol is not a meaning in itself.
By extension, Libra rules lawyers and diplomats. All are related to the idea that we are evolving to oneness with each other, and along the way we learn little-by-little how to do that without losing our own identity along the way.