The world's most authoritative text on the techniques of meditation is the Yoga Sutras of Patanjali. Patanjali was a great sage who lived in India about 1800 years ago; he codified the various teachings then current and produced the system universally known as Raja Yoga. His Yoga Sutras are a practical handbook not an academic treatise and are essential reading for all serious students of yoga. Patanjali commences his Sutras with his own definition which simply states: "Yoga is the control of thought waves in the mind". This Sutra (Book 1, No. 2) has been translated in various ways but its essence is clear: if you could still your mind, even for a moment, then you would experience Divine union (which is the real meaning of the word yoga). But Patanjali also means the process as well as its culmination: in other words, meditation is the means of controlling the thought waves in the mind, which eventually leads to the mystical consummation of yoga.

How to achieve this state is the main object of Patanjali's teaching. Raja Yoga actually involves an eightfold system (the so-called Eight Limbs of Yoga), but the first five 'limbs' are preparatory, while the last three are directly concerned with what we style as meditation. However, the first five cannot be neglected because they provide the bedrock on which later success in meditation lies. The first two 'limbs' are yama and niyama, best understood as moral do's and don'ts. Whilst morality is sometimes subjective, every true spiritual path springs from an ethical base, requiring personal endeavour to overcome the demands of the senses and to channel our energies in harmonious ways. The third 'limb' is asana, which means posture. All Patanjali suggests here is that you should be upright and steady: it is obvious that you cannot meditate successfully if you are in serious discomfort and unable to lose body-consciousness. The fourth 'limb' is pranayama, which entails special breathing exercises to calm the mind and control our inner energies. Although pranayama is certainly very beneficial, it can cause damage to the nervous system if incorrectly done, and for this reason must never be undertaken without expert guidance. Moreover, pranayama is not necessary in basic meditation - as distinct from calm, rhythmic breathing which is crucial in settling the mind. It is this latter that we must develop in the early stages. The fifth and last of the preparatory 'limbs' is pratyahara, which means sense restraint and involves the progressive withdrawal of our senses from seeking external gratification in order to intensify inner concentration. Pratyahara commences the all-important process of interning the mind.

Thus properly prepared, the yogi can commence the inward path itself. Raja Yoga's three final 'limbs' are dharana (concentration), dhyana (meditation) and samadhi (the state of illumination or absorption in which the yogi becomes one with the object of his meditation). These three are not separate activities but progressive states of mental control; Patanjali describes the whole process by one word samyama, in the same wider sense that we often use the term meditation.

When we concentrate, we start to focus the wayward energies of the mind and to direct our attention towards one chosen object. Once we have succeeded in concentrating the mind then, and only then, can meditation begin for dhyana is sustained attention to our chosen point of focus. Eventually, by prolonged practice of dhyana, the mind will become totally still, in which case the state of samadhi will naturally arise and it is in this state of samadhi that the yogi experiences the Divine.