I believe all suffering is caused by ignorance. People inflict pain on others in the selfish pursuit of their happiness or satisfaction. Yet true happiness comes from a sense of inner peace and contentment, which in turn must be achieved through the cultivation of altruism, of love and compassion and elimination of ignorance, selfishness and greed.

All suffering is caused by ignorance. People inflict pain on others in the selfish pursuit of their own happiness or satisfaction

118. Q. Why does ignorance cause suffering? A. Because it makes us prize what is not worth prizing, grieve when we should not grieve, consider real what is not real but only illusionary, and pass our lives in the pursuit of worthless objects, neglecting what is in reality most valuable.

For a man’s life would become intolerable, if he knew what was going to happen to him. He would be made aware of future evils, and would suffer their agonies in advance, while he would get no joy of present blessings since he would know how they would end. Ignorance is the necessary condition of human happiness, and it has to be admitted that on the whole mankind observes that condition well. We are almost entirely ignorant of ourselves; absolutely of others. In ignorance, we find our bliss; in illusions, our happiness.

All joy in this world comes from wanting others to be happy, and all suffering in this world comes from wanting only oneself to be happy. — Shantideva

(…) creation itself is rooted in ignorance; matter itself is ignorance. Not to know, and not to know that one does not know, is the cause of endless suffering.

Strange, that ignorance should be our best happiness in this life, and yet be the one we are ever striving to destroy !

We create most of our suffering, so it should be logical that we also have the ability to create more joy. It simply depends on the attitudes, the perspectives, and the reactions we bring to situations and to our relationships with other people. When it comes to personal happiness there is a lot that we as individuals can do.” •

We all live, but we don't know the why or the wherefore. We all live with the object of being happy; our lives are all different and yet the same.

Every single being, even those who are hostile to us, is just as afraid of suffering as we are, and seeks happiness in the same way we do. Every person has the same right as we do to be happy and not to suffer. So let's take care of others wholeheartedly, of both our friends and our enemies. This is the basis for true compassion.

May all sentient beings enjoy happiness and the root of happiness. May we be free from suffering and the root of suffering. May we not be separated from the great happiness devoid of suffering. May we dwell in the great equanimity free from passion, aggression, and prejudice.

Ignorance is the necessary condition, i do not say of happiness, but of life itself. If we knew everything, we could not endure existence a single hour. The sentiments that make it sweet to us, or at any rate tolerable, spring from a falsehood, and are fed on illusions.
If, like God, a man possessed the truth, the sole and perfect truth, and once let it escape out of his hands, the world would be annihilated there and then, and the universe melt away instantly like a shadow.

From the moment of birth, every human being wants to discover happiness and avoid suffering. No differences in our culture or our education or our religion affect this. From the very core of our being, we simply desire joy and contentment. But so often these feelings are fleeting and hard to find, like a butterfly that lands on us and then flutters away.

At the root of all the harm we cause is ignorance.