Many paths in magick include ideas of duality: God/Goddess, yin/yang, light/dark, matter/energy. Even the Tree of Life in Qabbalah is dual, with a third path in the middle signifying balance between the two. So what's the big deal about balance?
To begin with, the world is made of many dualities. We would not know light if there were never dark. We would not know pleasure if there were no pain. All happiness is due to the absence of sorrow. We have seen what happens to people who have a God but not a Goddess. Would a Goddess without a God be any better? It is this dichotomy that our ancestors realized, and built many logical belief systems around (Taoism, Wicca, Hinduism, Shamanism).
When we think about the duality of nature, we can see that too much or too little of light or dark, matter or energy, male or female would make our world a more difficult place to live in. Plants wouldn't grow in a healthy way; children would not be easily conceived, born or raised in a healthy environment. Socially, too much of any one emotion, even happiness, sets our family, friends or co-workers out of balance and takes us further from a comfortable social order. Our ancestors recognized this and created myths that illustrated what happened when a human, a moral code or a community went out of balance (Persephone, Orestes, Isis). The metaphysical concept of balance is one that most native peoples have never fallen away from. American Indians understand the balance between earth and sky, spirit and matter, long-range and immediate; for one discussion of this balance in Indian thinking, see Seven Arrows, by H. Storm. Historically, balance, physical and mental, has always had a place in human belief systems.
In the modern day, it is science that expands our concepts of balance. It is a scientific fact that humans think differently with the right side of their brains than with the left. To the right side of your brain is attributed creative thinking, original ideas and artistic tastes. To the left side of your brain is attributed linear thinking, mathematics and logical reasoning. Because we all have both sides in our brains, all humans have a creative side and a reasoning side. You can't balance your checkbook or dig a hole while thinking creatively, and you can't write a letter or decorate your home with linear thinking. Okay, you can, but they don't come out right, and you will be dissatisfied with the results. Therefore, it benefits all magicians and energy-workers-in-training to learn to use both sides of the brain equally.
There also exists a balance between conscious mind and subconscious mind. Sigmund Freud was the first to document this dichotomy. The conscious mind works on a level of societal integration. It includes the things we learn about living with other people, and its rules depend on which society we are born into. The conscious mind is the mannered, social side of us that keeps us from blurting out, "You stink!" to the person next to us when that person could use a shower.
The subconscious or inner part of our brains is the part that houses our magickal True Will, what we really should be doing. The True Will is present in all humans and will be appropriate no matter which society we are in. If your True Will is to be a teacher, a builder or an artist, this Will can be manifested wherever you are born.
If the conscious and subconscious mind don't line up together and work in unison, the human being becomes very dissatisfied with his or her environment. In the world, we are surrounded by people who are offensive to us, situations that we cannot tolerate and unpleasant emotions that come up inside of us unbidden. To keep to your Will amidst conflict does not mean rolling over to give in to the conflict; it means doing your Will in a way that does not inflict harm on others. Balance between conscious and subconscious allows one to act on one's Will and therefore enjoy one's environment. When we have the tact to say politely, "Please shower more," instead of "You stink!" when someone needs to hear it, we bring out the best in the people around us, rather than allowing annoyances to build up inside of our heads. On this topic, see Heal Your Body by Louise L. Hay.
On another level, when a mage uses all of his or her energy to bring about changes, he or she must be in balance between right/left and conscious/subconscious. If the consciousness is overriding any desires of the subconscious, those underlying desires will manifest in the outcome of the magick. To put it another way: If the work requires the use of right-brain thinking and you are stuck in a left-brain mindset, you will be dissatisfied with the results. So how do you stay in balance through your daily life so that you can utilize the best of your ability in magick?
To demonstrate, I'll begin with an exercise. Stand up right now, wherever you are sitting, and lift one foot. Make sure you are balanced, then pay attention to the foot that is still on the floor. What is it doing? It's making tiny adjustments to keep your center of gravity where it should be. This is how we learn to balance. We make tiny adjustments to our paradigm as we live day to day. No one is ever completely balanced all the time. However, knowing that balance requires tiny adjustments being made constantly is a first step.
Our minds get out of balance when we make "always" or "never" statements. If you always need to have things a certain way, does it make you uncomfortable if it is not that way? If you never react to a situation that requires reaction, will you be able to act upon your Will? Examine your own behavior for always and never statements, and realize that there are times when the mindsets they indicate will not suit your needs. These statements will keep your paradigm inflexible, unable to make those tiny adjustments necessary to keep yourself in balance. You may even find that when your always and never statements are challenged, you go way off balance! This is a big clue in examining our behavior.
We also can get out of balance when we try to push ourselves to do more than what we can do, or less than what we should do. This happens when we try to accomplish right-brain, creative projects with left-brain, rational thinking, or when we try to be rational with our creative right brains. Either way, the result is one that we are not going to be happy with.
Modern medicine tells us that dominant-hand tasks are ruled by the opposite side of our brains; left-handed people have more activity in the right side of the brain, and right-handed people show more activity in the left side of the brain. Studies done by psychologists and neurologists have proven that left-handed people tend to be more creative and right-handed people tend to be more rationalizing. Recent studies involving people with brain damage also show that all of us can learn to use both sides of the brain as effectively, according to Inside the Brain by Ronald Kotulak.
Ancient Hindu Yoga goes a step further and gives us the idea that our breathing can affect which side of our brains we are thinking with. According to ancient Hindu scriptures, it is possible, with concentration, to switch sides of your brain by simply covering one nostril and breathing through the side of your nose opposite the side of your brain you wish to use. In other words, if you wish to think creatively with your right brain, cover your right nostril. Once you get the hang of this, it is easy to simply tilt your head to the right, and after a few moments you will discover you are thinking more creatively. This also works, of course, with the left side/reasoning brain. Tantra, the Yoga of Sex, by Omar Garrison, discusses such breath work in further depth.
When going into a magickal rite, it's useful to make sure you are breathing on the side that corresponds to the work you are doing. If you are casting a money spell, you will want to work with your left brain. If you are asking for ideas on a project, or a creative compromise to a problem, try working with the right side.
In general, never go into a magickal rite if you feel totally out of balance. Your physical body will be affected if you are very much out of mental balance; you can always test yourself by finding a curb to walk along, the top of a rounded rock to stand on or simply standing on one foot. Tiny adjustments being made to keep you upright are normal; that means that your brain knows how to be in balance. However, if you suspect your mental balance is not where you would like it, how you balance physically in this exercise will confirm or deny that suspicion. If you're off-balance mentally, your physical body won't know when to make those tiny adjustments, and you will struggle to keep upright.
To acknowledge your mind and the way it works is to acknowledge yourself as your own higher power. To be in balance within yourself is to be in line with your True Will, allowing nothing to throw you off of it. To be in line with your True Will is to be in balance with the Earth, the solar system and the universe. You have the power to make your personal universe an easier place to live in, if you simply strive for balance, making those tiny adjustments to your paradigm every day and dropping any ironclad paradigms and "always and never" statements.
Keeping yourself in balance is hard work, but well worth it in the long run. You will find you have more energy, better psychic awareness and a better attitude, and most of all, you will enjoy your environment more.