Where “meaning” or “meaningfulness” is what makes things valuable, purposeful, or worth doing, consider the connection between meaning and time: we typically judge what is worthwhile according to what is worth our while. Ideally, the existential ‘worth’ appropriately corresponds to the temporal ‘while’ it took to achieve it. Hence, we say we ‘waste our time,’ while we do things not worth doing.
Now suppose naturalism is true. Life is finite and death is final. The moments that together constitute my life are the only moments I will have. Every passing breath brings me closer to the annihilation of my self. Thus, naturalists would seem to have a stronger impetus to make more worth their while than theists, because wasted time is literally wasted life. So, in an ironic turning of the tables, the naturalist could argue life is more meaningful given naturalism than theism: Does anyone have more motivation to “make the most out of every moment” than the naturalist? As a naturalist, would there be anything more foolish than choosing to not make the most out of every moment of my life?
But granting this is so, it’s almost as if each moment of life is so pregnant with meaning that it would be impossible to fully grab. The worth could never appropriately correspond to the while because nothing seems worth as much as the while. The value of my time will always exceed the value of anything I could be spending my time doing. Suppose there is something worth my while; namely, whatever is the most I could be getting out of any moment. If I’m not making the most out of this moment, I’m wasting my life. But how can I ever be sure I’m making the most out of the moment? Isn’t there always the possibility that there’s something else I could be “getting more out of”? But don’t think about it, because time’s a’wastin’! The anxiety is liable to produce despair. It an ironic re-turning of the tables, too much meaning might result in meaninglessness.