Early on in the sutras, we were told that abhyasa, practice, leads to citta-vritti-nirodhah, the control of the activities of the mind. Now, Patanjali tells us what exactly practice is. It is eka tattva – one principle. If we fix our minds on one object, we will prevent the nine obstacles from arising, eliminate the four associated symptoms, and cultivate the habit of an even, calm steady state of mind. There are seven options for eka tattva. The first, explained in sutra 1.33, is probably one of the most well known sutras in the entire text: maitri-karuna-muditopekshanam  sukha-duhka-punyapunya-vishayanam bhavanatash citta-prasadanam By cultivating the attitudes, bhavanas, of friendliness and love, maitri, for those who are happy, compassion and mercy, karuna, for those who are suffering, joy and go