This is a question I recently received.

There are three types of practitioners and three paths of yoga:

For the sattvic (pure minded/intelligent) type there is Raja or Jnana Yoga. This is the yoga of discrimination/analysis, the yoga of philosophical inquiry, the direct path of/to knowledge.

For the rajasic (distracted/passionate minded) type there is Karma (Ashtanga) Yoga. This is the path of action, the indirect path through use/exercise of the physical body to calm down the mind.

For the tamasic (those will more attachment) type there is Bhakti (devotional) Yoga. This is the path of the religious minded and for those with lots of material attachments, whether they be to physical objects, the body, name or fame. Here the mind is bonded (yoked) to blind faith. For this type of student, Ishvara Pranidhana means surrender to God.

In practice, a combination of the three paths, in different proportions, depending on the individual, is suitable for most people. We all need a bit of faith, physical exercise to reduce stress and discrimination to reach the final goal. All yogic paths culminate in Jnana (knowledge).

Yoga Sutra is not a religious text, though some people (including T Krishnamacharya) project religious values onto it.

In Raja (Patanjali) Yoga, Ishvara Pranidhana means giving up the attachment to the ego (false self) in favor of the true, inner Self. It is the path of self enquiry, the effort to know oneself, not the personality or character but one's true inner being.

According to yoga, while the mind is individual and related to a specific body/brain, history and set of experiences. Ishvara, the inner Self, is of the nature of universal consciousness. It is not specific, concrete or located in one place.

Pranidhana means to approach - ie IP means to seek out and find the true Self, pure consciousness, universal truth. It is also interpreted as surrender - ie the giving up the personal (passionate) agenda in favor of (pure/virtuous) universal values. Why would that be necessary?

Passion, emotion, attachment, ego, anger, fear - these stand in the way of objective reason and perception. With emotion, one projects prejudice, hopes and fears onto one's perception of reality - this distorts what one sees or understands to be true. In order to perceive the objective truth, one needs to develop some degree of detachment or equanimity, one needs to lay aside passion and a personal agenda to see clearly and without prejudice.

Samadhi, or yoga, is a different kind of knowing. It is one that requires a change, an evolution/transformation of the personality. Projections of the ego prevent objectivity - passion stands in the way of the tranquility, the steadiness of mind, required for meditation.

You cannot just "do" meditation. You have to change. You have to surrender the ego - not just in the moment (that is impossible) - it requires a permanent transformation of the personality.

Some people worry that developing equanimity means losing interest in important activities and connections with loved ones, however, this is not found to be the case. Surrender of the ego leads to the adopting of universal values of "goodness" - it means valuing what truly serves others, not what apparently serves in the short term.

It means that love and joy increase, not decrease, but it means that love becomes purer and less vulnerable to the vicissitudes of passion. Love means valuing the freedom, joy and truth of others, not projecting one's own personal values and agendas onto them.

For the individual, developing detachment not only facilitates the possibility for meditation, Self knowledge or Realization, it also leads to deeper peace, joy, fulfillment and effectiveness in all spheres.

Samādhisiddhirīśvarapraṇidhānāt - YS 2.45

"Perfection in samadhi is attained through iśvara-praṇidhāna."