Introduction:

Caricature Sketch by M.R.P.
Where is one left, after four weeks of discussing morality, if the conclusions reached are primarily that humans would do well to approach situations of moral choice with earnest, humble attention to nuance and detail? Well, some of the background assumptions which have led to this formulation are somewhat grander, such as that the apparent objectivity of some basic moral strictures may be an expected piece of a socially evolved mind, or that the justifications for trusting most proposed sources of moral knowledge are on equally dubious footing.
So, if by some chance you are willing to grant that I might be on the right track with both the grand propositions and the simple conclusions, then you might think that we are actually left in a somewhat sorry state, as moral actions then lack the special significance for which they are often revered. In responding to that charge, one can refer to some remarks of Thomas Nagel on the experience of absurdity, and on when mattering matters.
Absurdity and a Meaningful Life:
The first question to ask would be, ‘how significant is significant enough?’ There are plenty of competing answers as to what makes one action or life matter more, or be more meaningful, when compared to another action or life. Much of the initial backlash against naturalistic and nihilistic systems stems from the notion that actions, when divorced from any supernatural meaning, cease to have any meaning whatsoever.
When pressed on this point, most supernaturalists would point to the fact that naturalistic depictions of the universe almost universally tend toward an inhospitable equilibrium, often called the heat death of the universe. With this end in sight, no action of any kind seems to really, truly matter. With neither a consciousness present for the assignation of value nor any intuitive possibility of the universe exiting that equilibrium, value would be impossible.
Or a concerned party might work on a shorter time scale, by pointing out that nothing they do now will matter in even a mere million years. Regardless of the time scale under study, the general strategy is the same. And to this strategy, Thomas Nagel—speaking of the foregoing notion as an insufficient account of the experience of absurdity—provides an excellent rebuttal:
It is often remarked that nothing we do now will matter in a million years. But if that is true, then by the same token, nothing that will be the case in a million years matters now. In particular, it does not matter now that in a million years nothing we do now will matter. Moreover, even if what we did now were going to matter in a million years, how could that keep our present concerns from being absurd? If their mattering now is not enough to accomplish that, how would it help if they mattered a million years from now?
Whether what we do now will matter in a million years could make the crucial difference only if its mattering in a million years depended on its mattering, period. But then to deny that whatever happens now will matter in a million years is to beg the question against its mattering, period; for in that sense one cannot know that it will not matter in a million years whether (for example) someone now is happy or miserable, without knowing that it does not matter, period. (Nagel 716-17)
Nagel is exposing an assumption in such ‘final outcome’ arguments which has been illustrated and explored by numerous philosophers over the years. The assumption is something along the lines of the following: ‘if the final outcome of the universe lacks value, no human life has meaning.’ This is where the argument relies on its conception of what constitutes worthwhile activity. Implicit in this assertion is the notion that an activity is not worthwhile unless it produces something of lasting significance. If there is nothing of significance or value at the final outcome of the universe (or, as Nagel points out, if there is nothing of significance now), then no human can be or produce anything of lasting significance, and so can not be involved in worthwhile activity, and so can not lead a meaningful life.

Sisyphus by Franz Stuck
But there are plenty of conceptions of worthwhile activity which do not make such huge demands. For instance, perhaps the reduction of pain, as Peter Singer suggests, is an intrinsic good which would lend meaning to any life, regardless of whether any such action will affect the end-state of the universe. The key point is that such ‘final outcome’ arguments contain an arbitrarily high valuation of the future. For anything to be significant, according to such arguments, it must be significant at the future point whereat the universe is at an end. Yet there is no justification in the argument as to why something being significant at that future point is any more important than something being significant at any point before that, including the present moment.
This idea has been explored by plenty of philosophers, and, if you like, you can hear it reformulated by two other naturalists in this video of the young philosopher behind the THUNK youtube channel and this video of acclaimed philosopher of ethics Shelly Kagan. Indeed, as both of those videos suggest, whether a naturalist believes in moral realism or moral anti-realism, meaning and morality are still vitally relevant to the short-term, if not the (infinitely) long-term, and a contractarian ethical system remains possible. Special significance is not necessary for significance.
Conclusion:
In conclusion, I will provide some closure on a related concern to that of whether our lives have the right kind of significance, raised by Thomas Nagel above, which is the instinct that they do not. Nagel terms this feeling absurdity, and he contends that it arises from an unavoidable conflict between the sustained seriousness of our pursuits and their apparent meaninglessness in our estimations. But far from trying to solve the issue of absurdity, Nagel embraces it.
It is on this point, of whether absurdity should be surmounted, that Thomas Nagel differs significantly from such prominent existentialists—previous thinkers on absurdity—as Jean-Paul Sartre and Albert Camus (at least in Camus’ earlier work). Where Camus would employ a scornful rebellion against absurdity, Nagel concludes that to become embittered against absurdity and to attempt to heroically conquer or despairingly lament it is to fail to grasp the thorough unimportance of one’s self and one’s reality: “If sub specie aeternitatis there is no reason to believe that anything matters, then that doesn’t matter either, and we can approach our absurd lives with irony instead of heroism or despair” (Nagel 727). Nagel offers the view that absurdity is a by-product of our self-knowledge, and is no cause for alarm.
Work Cited:
Nagel, Thomas. “The Absurd.” The Journal of Philosophy 68.20 (1971): 716-27. JSTOR. Web.
When Mattering Matters: