Self-preservation is the first law of nature - Proverb for January 27

Our proverb for January 27 of "The Worlds Greatest Proverbs" is that "Self-preservation is the first law of nature."  The idea behind this proverb is that all living things will fight to survive.  Additionally that people will look out for themselves first.  While this may be true in many situations I don't believe this is universal.  We have all heard stories of people who have sacrificed something, even their own life in some extreme situation, for another.  Some examples are a parent sacrificing their life to save a child,  a firefighter for the life of someone in trouble, and every soldier who has gone to battle for another.  With that in mind I don't find this proverb very agreeable.