I would say, Taoist. Basically, 'before you build a bridge, ask is a bridge necessary in the first place,' and 'a tiger chooses to either strike or not strike, it does not fail to strike.'
We have -ist, -ism, and the root with no suffix at play (i.e., Taoist, Toaism, and Tao).
Wikipedia on Toaism:
a [philosophy] which emphasizes living in harmony with the Tao
And Tao:
Tao is the natural order of the universe whose character one’s human intuition must discern in order to realize the potential for individual wisdom. This intuitive knowing of “life” cannot be grasped as a concept; it is known through actual living experience of one’s everyday being.
I think the Webster definition about long life and fortune through magic is suspect, but it is not really a secular term. "Zen like" is very similar (via Buddhism). "Naturalist" I would say is not, its more like a green heart hippy vibe, idk. "Accepting" is just a gerund, cmon, now.
@FumbleFingers "fatalist" is also good.