How can we validate the existence of causality? The Buddha once said that it is not so easy for an ordinary person to prove the existence of cause and effect, but it’s not impossible. Buddhism contains the doctrine of the dependent arising of all compounded phenomena. What is dependent arising? It means that cause begets effect. All phenomena are the manifestations of dependent arising, the results of conditioned origination. Suppose a person killed an animal. This caused great harm to that animal. How can there be no consequence for the person who committed such grave karma? Like casually throwing a seed into moist and warm soil, it will germinate on its own with no tending required. By the same token, in the phenomenal world, every cause must bear its own fruit with no exception.
~ Luminous Wisdom Book Series 1: On Cause and Effect