@TickTockMan,
Albert Schweitzer (philosopher, doctor, and Nobel prize recipient) posited a particularly good philosophy called "reverence for life."
The main gist of "reverence for life" is that you go about your life and how you live it, but do no harm intentionally. If you step on a spider by accident for example, you cannot be at fault because there was no malicious intent towards that spider, it was only an accident. In doing so, you maintain a reverence for life but also accept the fact that there are bad things and accidents that do happen. As long as it is not intentionally done.
The notion of "who's life is more important" is actually a very interesting, which is probably why I like Schweitzer's theory in this instance. The concept of ego is also addressed in the theory by considering any intentionality of going out of the way to harm something or someone.
We can learn much from Albert Schweitzer... as well as appreciate the sheer magnitude of his mustache.