The first phrase is meant to caution me not to act if I would be acting out of anger or guile, and to remember that intentions matter in ethics. The second phrase is a reminder to be cautious even when my intentions are good.
This is so hard to express. It's about recognizing our (apparently) unique position in the vast cosmos as thinking, feeling creatures; and recognizing the inherent worth of our experience over say, the non-experience an asteroid might have.
Having and open mind is good as long as you are still learning things that are helping you form an opinion. To never form an opinion is to be intellectually lazy, and therefore useless.
It's far too easy to rely on well-worn arguments, but doing so can close your mind to new ideas. It's frustrating when your opponents do this, don't be guilty of it yourself.
Many of civilization's social problems arise from the lack of empathy. We categorize ourselves and others constantly—unknowingly and for the sake of comprehending the world's complexity. However, by creating the "other" we lose compassion for those who we've deemed unlike us.
For mankind to progress forward, individuals with the ability to affect change for the better have no right to waste their lives in empty pursuits. We all owe a debt to future generations to move civilization forward.
In systems where oppression is institutionalized (patriarchy, white supremacy, etc.), the privileged class is taught they they have a "right" to the benefits that are conferred upon them. But a "right" is something everyone should have.
We should only compare ourselves with the person we were yesterday. Making the world a better place starts with the person in the mirror. We are all capable of improving the world around us by sharing our creativity & knowledge or by simply relieving the suffering of others.