Raja yoga, is the royal path of meditation. As a king maintains control over his kingdom, so can we maintain control over our own "kingdom"—the vast territory of the mind. In raja yoga we use our mental powers to realize the Atman through the process of psychological control.

The basic premise of raja yoga is that our perception of the divine Self is obscured by the disturbances of the mind. If the mind can be made still and pure, the Self will automatically, instantaneously, shine forth. Says the Bhagavad Gita:

When, through the practice of yoga,
the mind ceases its restless movements,
and becomes still,
the aspirant realizes the Atman.

If we can imagine a lake that is whipped by waves, fouled by pollution, muddied by tourists and made turbulent by speedboats, we'll get a fair assessment of the mind's usual state.

Should anyone doubt this assertion, let the intrepid soul try to sit quietly for a few minutes and meditate upon the Atman. What happens? A thousand different thoughts fly at us, all leading the mind outward. The fly buzzing around suddenly becomes very important. So does the thought of dinner. We now remember where we left the keys. The argument we had yesterday becomes even more vivid and powerful; so does the perfect retort that we've cleverly composed during our "meditation." The minute we stop thinking one thought, another jumps in with equal force. Were it not so dismaying, it would be funny.

Most of the time we remain unaware of the mind's erratic movements because we are habituated to giving our minds free reign: we've never seriously attempted to observe, let alone train the mind. Like parents whose indiscipline has created children that everyone dreads, our lack of mental discipline has created the turbulent, ill-behaved minds that have given us endless difficulty. Without psychological discipline, the mind becomes the mental equivalent of the house ape. And all of us, sadly enough, have suffered mental agony because of it.

Mastering the Mind
While we may have grown accustomed to living with an uncontrolled mind, we should never assume that it's an acceptable, if not inevitable, state of affairs. Vedanta says that we can master the mind and, through repeated practice, we can make the mind our servant rather than being its victim. The mind, when trained, is our truest friend; when left untrained and reckless, it's an enemy that won't leave the premises.

Now, instead of the polluted lake we previously envisioned, think of a beautiful, clear lake. No waves, no pollution, no tourists, no speedboats. It's clear as glass: calm, quiet, tranquil. Looking down through the pure water, you can clearly see the bottom of the lake. The bottom of the lake, metaphorically speaking, is the Atman residing deep within our hearts. When the mind is pure and calm, the Self is no longer hidden from view. And, Vedanta says, that mind can be yours.

How? To again quote the Bhagavad Gita:
Patiently, little by little, spiritual aspirants must free themselves from all mental distractions, with the aid of the intelligent will. They must fix their minds upon the Atman, and never think of anything else. No matter where the restless and unquiet mind wanders, it must be drawn back and made to submit to the Atman alone.

The mind is cleansed and made tranquil through the repeated practice of meditation and through the practice of moral virtues.

Popular wisdom aside, there is no way to practice meditation without practicing moral virtues in tandem. To try to do otherwise is as effective as sailing the ocean with a leaky boat.

For such a Herculean task as realizing the Atman, all areas of the mind must be fully engaged. We cannot compartmentalize our life and assume that we can have both a "secular" area (in which we can live as we please) and a "spiritual" area. Just as we can't cross the ocean in a leaky boat, so we can't cross the ocean with two legs in two different boats. We must fully integrate all aspects of life and direct our energies towards the one great goal.

This doesn't mean that in order to realize God a person must totally renounce the world and live in a cave, monastery or convent. What it does mean is that all aspects of our life must be spiritualized so that they can be directed towards attaining the goal of God-realization.

Because raja yoga is the path of meditation, it is—when practiced exclusively—generally followed by those who lead contemplative lives. Most of us will never fall into that category. Raja yoga is, however, an essential component of all other spiritual paths since meditation is involved in the loving recollection of God, mental discrimination, and is an essential balance to selfless action.