(Because) the notion of absolute truth is difficult to sustain outside the context of religion, ethical conduct is not something we engage in because it is somehow right in itself but because, like ourselves, all others desire to be happy and to avoid suffering. Given that this is a natural disposition, shared by all, it follows that each individual has a right to pursue this goal. Accordingly, I suggest that one of the things which determines whether an act is ethical or not is its effect on others' experience or expectation of happiness.
Dalai LamaWhere there is a mind, there are feelings such as pain, pleasure, and joy. No sentient being wants pain: all wants happiness instead.
Dalai Lama