Could you give me a definition of "life for life's sake"? It is related to Thoreau and his essay "Life Without Principle".
Thoreau's essay is, summarised in the broadest possible terms, an argument that life isn't worth living if it's lived simply for money.
"Life for life's sake" is the principle that you should enjoy your life, and live your live for what you do - not for exchanging what you do for money, and then living off that. It's a principle of "present moment" enjoyment which argues that money is not a good reason to live your life.