“When the word Yoga is mentioned, most people immediately think of some physical practices for stretching and stress reduction. This is one aspect of the Yogic science, but actually only a very small part and relatively recent in development. The physical Yoga, or Haṭha Yoga, was primarily designed to facilitate the real practice of Yoga—namely, the understanding and complete mastery over the mind. So the actual meaning of Yoga is the science of the mind.”

Satchidananda opens his Introduction by directly addressing the common view of Yoga as primarily physical exercise. He redefines Yoga by shifting the emphasis from the body to the mind, presenting it as a discipline for understanding and mastering mental activity.

“The restraint of the modifications of the mind-stuff is Yoga.”

By quoting Patanjali’s sutra defining Yoga and immediately following it with his own commentary—“For a keen student, this one sūtra would be enough because the rest of them only explain this one”—Satchidananda highlights this teaching as the foundation of the entire text.

“That is why Yoga does not bother much about changing the outside world. There is a Sanskrit saying, ‘Mana eva manuṣyanam karaṇam bandha mokṣayoḥ.’ ‘As the mind, so the person; bondage or liberation are in your own mind.’ If you feel bound, you are bound. If you feel liberated, you are liberated. Things outside neither bind nor liberate you; only your attitude toward them does that.”

Satchidananda explains that the source of human suffering and freedom lies in the mind rather than external circumstances. By stating that Yoga focuses less on changing the outside world than on transforming one’s mental attitude, he presents self-reformation as the path to liberation.

“In the same way, the Seer, or true you, reflects in the mind which is your mirror. Normally, you can’t see the true Self because your mind is colored. If the mind is dirty, you say, ‘I am dirty.’ If it’s all polished and shining, ‘I am beautiful.’ That means you think you are your reflection in the mind.”

Satchidananda makes the abstract relationship between the Self (Seer) and the mind comprehensible through the metaphor of a mirror. This analogy shows that people often mistake the changing condition of the mind for their true nature. Yoga seeks to calm and purify the mind so that the true Self can be seen clearly.

“Whatever the thought is, if there is no selfishness behind it, it can never really bring pain to the person concerned. The result is neither pain nor pleasure, but peace. Seeing this truth, we should analyze all our motives and try to cultivate selfless thoughts. That is our first and foremost duty.”

Satchidananda explains that thoughts rooted in selflessness lead to lasting peace. He encourages readers to examine their motives and cultivate selfless thoughts as part of their daily practice, presenting this as an essential step toward inner peace.

“These mental modifications are restrained by practice and non-attachment.”

After quoting the sūtra, Satchidananda explains that practice and non-attachment work together to quiet the mind. He describes practice as the continual effort to steady the mind and non-attachment as letting go of the desires that disturb it.

“Immediately somebody will ask, ‘If you are unattached, won’t you lose all incentive and become dull?’ No. When we say unattached, it means without personal desires. If you really want to be greedy, be greedy in serving others.”

Satchidananda clarifies that non-attachment does not mean becoming passive or indifferent. Instead, he explains that it involves giving up personal desires while directing one's energy toward serving others.

“Whether you are interested in reaching samādhi or plan to ignore Yoga entirely, I would advise you to remember at least this one sūtra. It will be very helpful to you in keeping a peaceful mind in your daily life.”

Here, Satchidananda highlights this sūtra as a practical teaching for everyday life. He suggests that its guidance can help anyone cultivate a peaceful mind, regardless of their interest in pursuing the full path of Yoga.

“But how can this burning process be effected with our mental impurities? By accepting all the pain that comes to us, even though the nature of the mind is to run after pleasure. We will actually be happy to receive pain if we keep in mind its purifying effects. Such acceptance makes the mind steady and strong because, although it is easy to give pain to others, it is hard to accept without returning it.”

Satchidananda explains tapas (austerity) as accepting life's difficulties with the understanding that they can purify the mind. He teaches that meeting hardship without retaliation strengthens mental steadiness and supports spiritual growth.

“The order is also significant: Because of ignorance of the Self, egoism comes. Because of egoism, there is attachment to things for the ego’s selfish pleasure. Because sometimes the things we are attached to do not come or are taken away, hatred for those who get in our way comes in. And, finally, because we are attached to things and afraid of death, there is clinging to life in the body.”

This passage traces the five kleśas as a chain of cause and effect beginning with ignorance (avidyā). Each obstacle arises from the one before it, showing that spiritual ignorance is the root from which the other forms of suffering develop.

“What is Self and what is non-Self? The Self is the eternal, never-changing One. It is always everywhere as the very basic substance. All things are actually nothing but the Self, but in our ignorance we see them as different objects. Thus, we take the changing appearances to be the unchanging truth. When something changes, it can’t be the Self.”

This passage explains that the Self is permanent and unchanging, while the body, mind, and external world are constantly changing. Recognizing this distinction helps correct the ignorance that causes people to identify with what is temporary instead of their true nature.

“I often refer to these two ‘I’s’ as the little ‘I’ and the capital ‘I.’ What is the difference? Just a small dot, a little blemish of ego. The capital ‘I’ is just one pure stroke, just as the highest truth is always simple and pure. What limits us and makes us little? Just the dot.”

The author uses a simple typographical metaphor to explain the relationship between the ego (“little i”) and the true Self (“capital I”). The ego is not a formidable enemy but a small blemish—a dot—that obscures our true, pure nature. Yogic practice is thus presented as a simple act of purification.

“When we do something several times, it forms a habit. Continue with that habit for a long time, and it becomes our character. Continue with that character, and eventually, perhaps in another life, it comes up as instinct.”

Satchidananda explains the metaphysical concept of instinct by grounding it in observable psychological processes. He presents a clear progression from repeated action to habit, from habit to character, and ultimately from character to instinct across lifetimes. This rationalizes reincarnation and karma by framing them as a natural extension of everyday experience.

“There are, then, three kinds of karmas: Those being expressed and exhausted through this birth (prārabdha karma); new karmas being created during this birth (āgami karma); and those waiting in the karmāśaya to be fulfilled in future births (sañjita karma).”

This explanation divides karma into three categories according to when its effects are experienced. By distinguishing between past karma unfolding in the present, new karma being created, and accumulated karma awaiting future expression, the passage clarifies how actions continue to shape spiritual progress over time.

“To one of discrimination, everything is painful indeed, due to its consequences: The anxiety and fear over losing what is gained; the resulting impressions left in the mind to create renewed cravings; and the constant conflict among the three guṇas, which control the mind.”

This passage explains that even pleasant experiences can become sources of suffering because they create attachment, fear of loss, and renewed desires. It encourages the practitioner to seek lasting peace beyond experiences that continually give rise to craving and dissatisfaction.

“The world is a training place where we learn to use the world without getting attached. Instead of saying, ‘To one of discrimination, everything is painful,’ it becomes, ‘To one of discrimination, everything is pleasurable.’ A person with such an understanding has the magic wand to convert everything into happiness. Pleasure and pain are but the outcome of your approach.”

Here, the author counters the potentially pessimistic conclusion that all life is pain. He argues that this realization is not an endpoint but the beginning of true mastery. With proper understanding, one can engage with the world skillfully, transforming it from a source of suffering into a place of joy.

“If the thought of hatred is in the mind, we can try to bring in the thought of love. If we can’t do that, we can at least go to the people we love and, in their presence, forget the hatred. So, although the hatred comes to the surface, we can keep it from coming out or staying long by changing the environment.”

The author provides a practical psychological technique for managing negative emotions like hatred. Instead of suppressing the feeling, he advises cultivating its opposite, love, or physically changing one’s environment to be around loved ones. This method empowers individuals to actively regulate their mental state by shifting their focus and external circumstances.

“We shouldn’t think samādhi means sitting in a corner, forgetting ourselves and keeping the body still like a rock. Real samādhi means tranquility of mind, which is possible only when we dedicate everything and are free from all attachment.”

Satchidananda challenges the popular image of samādhi as a static, world-denying trance. He redefines it as a dynamic state of mental tranquility that is accessible in daily life. This peace is not achieved by physical withdrawal but through the inner practice of selfless dedication and freedom from all attachments.

“This very practice itself is called concentration: The mind running, your bringing it back; its running, your bringing it back. You are taming a monkey. Once it’s tamed, it will just listen to you. You will be able to say, ‘Okay, sit there quietly.’ And it will. At that point you are meditating. Until then you are training yourself to meditate. Training your mind to meditate is what is called dhāraṇā.”

Using the image of taming a monkey, Satchidananda explains that concentration (dhāraṇā) is the repeated practice of bringing the wandering mind back to its object of focus. He distinguishes this training from meditation, which begins once the mind has become steady.

“These [superphysical senses] are obstacles to [nirbija] samādhi but are siddhis (powers or accomplishments) in the worldly pursuits.”

The author features this sutra to introduce an important paradox in the spiritual path. By stating that the powers are both real accomplishments and severe obstacles, he forces the reader to confront the subtle temptations of the ego. This sets up his subsequent argument that non-attachment must extend even to the fruits of spiritual practice itself.

“By non-attachment even to that [siddhis], the seed of bondage is destroyed and thus follows kaivalya (independence).”

This sūtra serves as the thesis statement for the author’s argument about the supreme importance of non-attachment (vairāgya). Letting go of attachment to siddhis removes the remaining cause of bondage and leads to kaivalya, the state of complete freedom.

“The perceived can never become the perceiver, nor vice-versa. If a perceiver is perceived by something, then he or she is no longer a perceiver but, rather, the perceived. To really have this awareness, this isolation of perceiver and perceived, is Yoga.”

Satchidananda clarifies the fundamental distinction between the perceiver (Puruṣa) and the perceived (mind). He asserts that this hierarchical relationship is absolute; the true Self is always the subject and never the object. Maintaining this awareness helps practitioners recognize the true Self as the unchanging witness rather than identifying with the changing activities of the mind.

“Ultimately, even the desire to get God should go. Then only will you have God. When will that desire go? When you get God! It’s kind of a tricky thing.”

Satchidananda explains that even the desire for spiritual realization is eventually left behind. The longing for God naturally disappears when realization is attained, because the seeker has reached the goal being sought.