I don’t know what nihilism is and how to distinguish it from similar views. For example, I don’t know for sure what the difference is between the nihilistic “nothing is good or bad so I just do what brings me pleasure” and the hedonistic “I just do what brings me pleasure because in the end nothing is really good or bad”. But it seems to me that there are, at a fundamental level, two different ways of defining nihilism.
Nihilism can either be an equality thesis: With respect to value or meaning everything is equal. Neither meaningful/insignificant nor good/bad allow us to draw any differences in the world because everything has the same meaning or value.
Alternatively, nihilism can be a universality thesis: Everything is meaningless or valueless. No matter where you look you won’t find any meaning or value.
Nihilism isn’t the only view that can both be understood as a thesis about equality and as a thesis about universality. A genuine egalitarian thesis is one that can’t be reformulated without loss as a universality thesis. For example, this criterion rules out (1) from being a genuine thesis about equality:
(1) Death makes us all equal.
For (1) can be reformulated as (2):
(2) We all must die eventually.
If everyone must die, it follows that we are the same with respect to our mortality. But our equality is just the consequence of this universal truth. (Of course, in other debates it’s by no means trivial to tell whether an egalitarian thesis is just a consequence of an underlying universality claim, see most notably the discussion about justice and equality.)
To return to nihilism: Many nihilists believe that everything has the same value/meaning because they think everything is valueless/meaningless. Those are universalistic nihilists. But what about those who don’t? Wittgenstein in the Tractatus is an interesting case:
6.4 Alle Sätze sind gleichwertig.
6.4 All propositions are of equal value.
Without going into details here, his argument is from the sameness of all propositions to all of them being devoid of value. Thus, he is an egalitarian nihilist, or so I read him.
A surprising consequence of this way of understanding nihilism is that you are a nihilist (not a pessimist/optimist) if you think that everything is always awful or that everything is always perfect. If everything is perfect, everything has the same value, hence egalitarian nihilism. That’s a welcome result. If everything is perfect, there seems to be no feature that makes something perfect, there is no reason why it is perfect, it could change completely without changing in value or meaning. To my ears that’s very close to outright nihilism. (Another author who is suspicious of the “everything is perfect” variety of optimism is Margaret Boden, see her “Optimism” in: Philosophy 41 (1966): 291–303. She thinks of “apriori optimism”, as she calls it, as merely a psychological phenomenon, as expressing merely a mood or some such, not as a philosophical thesis.)
