The word yoga is derived from the Sanskrit verb yuj
meaning bind, join, unite, control.
It is allied to the English word yoke, the German joch,
and the Latin jungo (I join).
Yoga thus literally means union and control.
It signifies the union of man with God,
of the individual with the universal reality,
of each with the All of existence.
It means union of the mortal with the eternal.
It implies union of the mind with the inmost centre
of one's own being, the self or atman -
union of the conscious mind
with the deeper levels of the unconscious -
resulting in the integration of personality.
-Haridas Chaudhuri
Yoga is a Sanskrit world meaning yoke or union...
the joining of a healthy body and disciplined mind 
for the purpose of spiritual growth.
-Diane Neuman
The word itself, which stems from the ancient Sanskrit language,
means both "union" and "discipline."
Thus yoga conveys "unitive spiritual discipline"
or "the spiritual discipline of integration."
-Georg Feuerstein
It (yoga) is a practice.
Literally the word "yoga" means
"a yoke that brings union".
It means bringing the finite (your body)
into the Infinite (your consciousness).
-Harbhajan Singh Khalsa, "Yogi Bhajan"
Yoga is union of the individual soul
with the Supreme Self.
-Chinmoy Kumar Ghose, "Sri Chinmoy"
Yoga means union.
The union of the individual soul
with the Universal Spirit is yoga.
-B. K. S. Iyengar
Yoga is the union of the individual psyche
with the transcendental Self.
-Yoga Vajnavalkya
Yoga is awareness,
transformation of the human consciousness
into divine consciousness.
-Jaideva Singh
The yogas help to unify body-force with mind-force 
and mind-force with spirit force,
all to bring equanimity rather than polarization to the mind.
-Neale Lundgren
Yoga is the practice of connecting
the senses of the soul with the senses of the body,
the heart with the mind, matter with spirit.
-Neale Lundgren
The real yoga is an everyday,
moment-to-moment state of alert awareness.
Consciously and with skill one walks the razor's edge
into the heart of God.
-Gitananda
The whole nature of the individual,
which ought to be homogeneous and whole,
becomes split and divided during his unawareness.
To restore its wholeness without a single seam or flaw
is the real aim of yoga.
-Nilankantha Sri Ram
Yoga is awareness, alignment and flow.
-Chetanananda
Yoga means harmony, union, integration.
There must be an inner harmony,
a total harmony within the total being.
-Vekantesananda
Yoga is the science of harmony.
-Shandor Remete
Harmony constitutes the essence of yoga.
-Nilakantha Sri Ram
Yoga is the art
of merging all differing forces into one.
-Shandor Remete
Yoga means to seek the union of nonduality,
so that everything becomes united as one.
-Peter Marchand
Yoga means union
in all its significances and dimensions.
-Indra Devi
Where does the body end and the mind begin?
Where does the mind end and the spirit begin?
They cannot be divided as they are interrelated
and but different aspects of the same all-pervading divine consciousness.
-B. K. S. Iyengar
The yogic journey guides us from our periphery, the body,
to the center of our being, the soul.
-B. K. S. Iyengar
Yoga is an interior penetration leading to integration
of being, senses, breath, mind, intelligence, consciousness and Self.
-B. K. S. Iyengar
The whole technique of yoga can be synthesized into five aspects -
proper exercise, proper breathing, proper relaxation, proper diet
and positive thinking and meditation.
-Vishnudevananda
I prefer to think of Yoga as "Four-fold Awareness".
1. Awareness of the body and how it works.
2. Awareness of the emotions and how they use the body.
3. Awareness of the mind
and how it can control the emotions and the body,
and transcend "itself" into the higher mind.
4. Awareness of "awareness" itself,
which is a higher mind experience.
-Gitananda
In my book, I divided the body into three parts:
the head: yoga of knowledge;
the chest: yoga of love;
the limbs: yoga of action.
How can you say one is higher and the other lower?
Three parts make the whole.
-B. K. S. Iyengar
Mind, spirit and body should be one:
three in one, and one in three.
-B. K. S. Iyengar
Yoga is the complete awareness
of your body, mind and emotions and of awareness itself.
-Gitananda
Thinking, feeling and willing -
they seem to run in different directions.
Integrate them and you have yoga in action.
-Venkatesananda
There are seasons in the mind,
great currents and winds move there,
the true yogi ties a rein to them;
a power plant he becomes.
-Kabir
Yoga is a way of moving into stillness
in order to experience the truth of who you are.
-Erich Schiffman
The spiritual development of a student of Yoga
depends upon two things.
First, he must eliminate the factor
that obscures the spiritual light
and secondly, he must be able to fix his wandering mind.
-Kuvalayananda
Yoga is the art and science
of disciplining the body-mind.
-Georg Feuerstein
Yoga means the disciplining of the intellect, the mind, the emotions, the will;
it means a poise of the soul 
which enables one to look at life in all its aspects evenly.
-Mahadev Desai 
The aim of yoga
is to calm the chaos of conflicting impulses.
-B. K. S. Iyengar
Yoga is the composed mind.
-Vyasa
Concentration of mind
is the key to Yoga.
-Sivananda
Yoga is settling the mind into silence.
-Patanjali
Equilibrium (evenness of mind) is yoga.
-Bhagavad Gita
It is the science of Yoga to know
and the art of Yoga to be united with the Highest
so that we may live in the Self
and act from that supreme poise.
-Aurobindo Ghose
The practice of yoga in the strict sense of the term
is to allow the power of Being
to work more and more freely within us.
-Haridas Chaudhuri
Yoga is the life in the Spirit.
It is the science of life,
of integral self-development,
of harmonious living.
-Sivananda
The whole educative thrust of yoga
is to make things go right in our lives.
But we all know that an apple can appear perfect on the outside
but be eaten away by an invisible worm on the inside.
Yoga is not about appearances.
It is about finding and eradicating the worm,
so that the whole apple, from the skin inward,
can be perfect and a healthy one.
That is why yoga, and indeed all spiritual philosophies,
seem to harp on the negative -
grasping desires, weaknesses, faults, and imbalances.
They are trying to catch the worm
before it devours and corrupts the whole apple from the inside.
So yoga insists on examining, scientifically and without judgement,
what can go wrong, and why, and how to stop it.
It is organic farming of the self - for the Self.
-B. K. S. Iyengar
Yoga is a sophisticated system
for achieving radiant physical health,
superb mental clarity, and therefore peace of mind,
as well as spiritual insight, knowledge and understanding.
It is a complete system for total psychosomatic spiritual health.
It's a way of learning to live in happy harmony with life.
-Erich Schiffman
Yoga is a canon of techniques 
used to aid the practitioner is coming to an understanding of the absolute.
-Edward Clark
The goal of Integral Yoga,
and the birthright of every individual,
is to realize the spiritual unity
behind all the diversities of the entire creation
and to love harmoniously as members of one universal family.
The goal is achieved by maintaining our natural condition of:
a body of optimum health and strength,
senses under total control,
a mind well-disciplined, clear and calm,
an intellect sharp as a razor,
a will as strong and pliable as steel,
a heart full of unconditional love and compassion,
an ego as pure as crystal,
and a life filled with supreme peace.
-Satchidananda
The Light that yoga sheds on Life is something special.
It is transformative.
It does not just change the way we see things;
it transforms the person who sees.
It brings knowledge and elevates it to wisdom.
-B. K. S. Iyengar
In yoga experience the consciousness widens in every direction,
around, below, above, in each direction stretching to infinity.
When the consciousness of the yogi becomes liberated,
it is not in the body,
but in this infinite height, depth and wideness that he lives always.
Its basis is an infinite void or silence, but in that all can manifest -
Peace, Freedom, Power, Light, Knowledge, Ananda.
-Aurobindo Ghose
The yoga we practice is not for ourselves alone, but for the Divine;
its aim is to work out the will of the Divine in the world,
to effect a spiritual transformation
and to bring down a divine nature and and divine life
into the mental, vital and physical nature and life of humanity.
-Aurobindo Ghose
Its aim is...to bring the supramental power of that divine consciousness
down into the ignorance of mind, life and body,
to transform then, to manifest the Divine here and create a divine life in matter.
-Aurobindo Ghose
Yoga is the art of doing everything
with the consciousness of God.
-Yogananda
Yoga is essentially an inner process.
-Sivananda
Yoga practice is internal.
-B. K. S. Iyengar
It is the aim of the Yogi to perfect himself,
and in so doing he attains spiritual bliss.
-Selvarajan Yesudian
Yoga, I often say, is like music.
The rhythm of the body,
the melody of the mind,
and the harmony of the soul
create the symphony of life.
-B. K. S. Iyengar
Self-purification
is one of the basic processes of yoga.
-Sivananda
To live immaculate
amidst the impurities of the world -
This is the true Yoga practice.
-Nanak
Yoga is the golden key
which unlocks the door
to peace, tranquillity and joy.
-B. K. S. Iyengar
In the beginning
you have to make room for yoga in your daily life.
But after some time
yoga will pull you up by the hair and make you do it.
-Vanda Scaravelli
The quality of your yoga, and your life,
depend solely on how interested you are in the doing of it.
-Erich Schiffman
Yoga must be lived
in the most earnest and devoted way -
breath-by-breath, thought-by-thought, day-by-day, for decades
as a way of life called Dharma.
-Bruce Burger
The most difficult posture in yoga
is the ever-changing posture of daily life.
-Peter Marchand
The pursuit of yoga requires
all the dedication, energy and will-power
a person can muster.
-Georg Feuerstein
Remember that committing to a daily practice,
as well as the struggle around this commitment,
is yoga!
-Julie Rappaport
There can be no halfway measures
if the true goal of Yoga is to be reached.
-Dane Rudhyar
Do the yoga that you understand
at the level that you understand it
and do it with full conviction.
-Muktananda
Yoga practice is a journey with no end.
-Baron Baptiste
Yoga is a light,
which once lit, will never dim.
The better your practice, the brighter the flame.
-B. K. S. Iyengar
Constant practice alone is the secret of success.
-Hatha Yoga Pradipika
Yoga is spirituality in practice.
-Sivananda
Make Yoga a spiritual reality
in your daily life.
Become a practical Yogi.
-Sivananda
The yogi is the man
who realizing the unity, lives it.
-Annie Besant
The practice of Yoga involves the whole person,
not only his waking consciousness but also the subconscious.
The yogin's spiritual quest entails
a complete reorientation of his entire life.
-Georg Feuerstein
In the right view both of life of Yoga,
all life is either consciously or subconsciously a Yoga.
-Aurobindo Ghose
Yoga asks, "What don't you know about yourself?"
-Donna Farhi
Yoga itself is the teacher.
-Vyasa
Yoga is an essential way of life.
To become one with one's body,
is to become one with life itself.
-Anonymous
Yoga is complete Life.
-Sivananda
Yoga is Self Love.
-Swami Dayananda
Verily, there is no merit higher than Yoga,
no good higher than Yoga,
no subtlety higher than Yoga;
there is nothing higher than Yoga.
-Yogansikha-Upanisad