The fundamental teaching of the Buddha is that we should view others as being more important than we are. Of course, you cannot completely ignore yourself. But neither can you neglect the welfare of other people and other sentient beings, particularly when there is a clash of interest between your own welfare and the welfare of other people. At such a time you should consider other people’s welfare as more important than your own personal well-being. Compare yourself to the rest of sentient beings. All other sentient beings are countless, while you are just one person. Your suffering and happiness may be very important, but it is just the suffering and happiness of one individual, whereas the happiness and suffering of all other sentient beings is immeasurable and countless. So, it is the way of the wise to sacrifice one for the benefit of the majority and it is the way of the foolish to sacrifice the majority on behalf of just one single individual. Even from the point of view of your personal well-being, you must cultivate a compassionate mind—that is that source of happiness in your life.
From Stages of Meditation, pages 71–72.