Like waves, all the activities of this life have rolled endless on, yet they have left us empty-handed. Myriads of thoughts have run through our minds, but all they have done is increase our confusion and dissatisfaction.
Normally we operate under the deluded assumption that everything has some sort of true, substantial reality. But when we look more carefully, we find that the phenomenal world is like a rainbow — vivid and colorful, but without any tangible existence.
When a rainbow appears we see many beautiful colors — yet a rainbow is not something we can clothe ourselves with, or wear as an ornament; it simply appears through the conjunction of various conditions. Thoughts arise in the mind in just the same way. They have no tangible reality or intrinsic existence at all. There is therefore no logical reason why thoughts should have so much power over us, nor any reason why we should be enslaved by them.
Dilgo Khyentse Rinpoche