The purpose of life is to live.
That's all I bother to preserve in the end, to desire to preserve, if you will: Life. It seems other sentient things are the main things worth valuing in my life.. I don't do this out of religion or some other established cause. I certainly don't do this selflessly. I choose to love life because I choose to -- selfishly.
I don't bother desiring a purpose. It's insipid and artificial as a concept. I just do what makes me happy. Life and its long-term sustention makes me happy. I only attack things I view as anti-life.
Anti-life (death/destruction?) is as natural as life. This is evident in nature as well. Life gives rise to death, and death is evident all around you. Not only is death all around you, but it sustains and gives rise to life. For there to be life, there must be death. Appreciating the good in anti-life assists in qualitative living, I find.
I see you're trying to be zen. Mr. Joint, of course I am not attached to the idea of an ideal world. I am also a proponent of natural selection. However, I will assert my preference for life when it is called for.
You can prefer all you want. Just don't be too disappointed if what happens isn't what you prefer.
A truism of Buddhist philosophy; attachment to desire is suffering. Gotcha.
I'm not a Buddhist, but I do believe it is true. Though, I would add that I think desire for things that have intrinsic benefit is a good type of desire. I think that all desire is suffering in the same way that a free-being can simultaneously erect its own constraints. Paradoxes are plausible.