I:2 Yogah Cittavrtti nirodhah
Yoga is cessation of movements in the consciousness.
1:3 Tada drastuh svarupe avasthanam
Then, the seer dwells in his own true splendor.
1:4 Vrtti sarupyam itratra
Other times, the seer identifies with the fluctuating consciousness.
1:5 Vrttayah panchatayyah klista aklistah
The movements of consciousness are fivefold. They may be congnizable or non-cognizable, painful or non-painful.
1:12 Abhyasa vairagyabhyam tannirodhah
Practice and detachment are the means to still the movements of consciousness .
1:13 Tatra Sthitau yatnah abhyasah
Practice is the steadfast effort to still these fluctuations.
I:33 Maitri karuna mudita upeksanam sukha dukha punya apunya visayanam bhavanatah cittaprasadanam
Through cultivation of friendliness, compassion, joy, and indifference to pleasure and pain, virtue and vice respectively, the consciousness becomes favorably disposed, serene and benevolent.

2:28 yoganganusthanat asuddhiksaye jnanadiptih avivekakhyateh
By dedicated practice of the various aspects of yoga impurities are destroyed, the crown of wisdom readiates in glory.
2:29 yama, niyama, asana, pranayama, pratyahara, dharana, dhyana, samadhayah astau angani
Moral injunctions, fixed observances, posture, regulation of breath, internalization of the senses towards their source, concentration, meditation and absorption of consciousness in the self are the eight constituents of yoga.
II:30 ahimsa satya asteya brahmacarya aparigrahah yamah
Non-violence, truth, abstention from stealing, continence and absence of greed for possessions beyond one's need are the five pillars of yama
II:32 Sauca santosa tapah svadhyaya isvarapranidhanani niyamah 
Cleanliness, contentment, ardous work, self study and surrender of self to divine within are the niyamah
II:34 Vitarkah himsadayah krta karita anumoditah lobha krodha moha purvakah mrdu madhya adhimatrah dukha ajnana anantaphalah iti pratipaksabhavanam
Uncertain knowledge giving rise to violence, whether done directly or indirectly, or condoned, is caused by greed, anger or delusion in mild, moderate or intense degree. It results in endless pain and ignorance. through introspection comes the end of pain and ignorance.