Albert Einstein:
A human being is a part of the whole called by us universe, a part limited in time and space. He experiences himself, his thoughts and feeling as something separated from the rest, a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty.
Sogyal Rinpoche:
...when we finally know we are dying, and all other sentient beings are dying with us, we start to have a burning, almost heartbreaking sense of the fragility and preciousness of each moment and each being, and from this can grow a deep, clear, limitless compassion for all beings.