I thought this was an interesting but odd tweet by the philosopher Stathis Psillos:
I’m not sure whether he means ontological idealism (the ultimate foundations of reality are mental) or epistemological idealism (there is no mind-independent reality, in the sense that we cannot know the world-as-it-is), but I guess he would apply it to both.
By intersubjective, he means that we seem to inhabit a shared reality. By modal, he means this:
If human experience is fundamental, how can we seem to inhabit a shared reality? His answer is that an external agent is required “who imposes structure on human experience.”
Leaving aside the points about the intersubjective and modal characteristics of the world, for a moment at least, the basic claim is that there is structure in our experience that seems to require an external agent. But you could make the same claim about materialism. The claim would be something like this:
The problem with materialism is that it seems to require an external agent that fixed the laws and constants of nature in a particular way.
In other words, materialism is vulnerable to the fine-tuning argument. Both materialism and idealism are monisms in which there are regularities and structures that may seem surprising. I’m not sure why that’s supposedly more of a challenge for idealism.
The idealist philosopher Bernardo Kastrup also addresses this type of argument in the following paper:
“Under physicalism, the laws of nature are seen as irreducible
causal patterns somehow built into the fabric of the cosmos. It is the
dynamic unfolding of these patterns that leads to the order and com-
plexity we see around ourselves. Under idealism, such irreducible
causal patterns are posited to be somehow built into universal con-
sciousness itself, instead of an objective fabric of space-time. Yet,
beyond this distinction, they are the same patterns that physicalism en-
tails, as inherent to consciousness as physical laws are allegedly in-
herent to the fabric of space-time. Idealism poses no extra difficulty
than physicalism in this regard.”
So Psillos seems to make the mistake of thinking that a fundamentally mental nature would be disordered, barring external intervention. But that is not a justified assumption. In fact, I think he’s making two dubious claims:
- The structure of reality is a challenge for idealism. But as mentioned above, this is not more challenging for idealism than it is for materialism.
- Our shared reality is a challenge for idealism.
Regarding the second claim, there are forms of idealism — e.g. a unitary form of cosmopsychism where we are all within the same consciousness — where intersubjectivity is not especially problematic. And I’m not sure that it is trivial for a materialist to make sense of intersubjectivity, given that humans do not perceive reality as it is.
So those two claims have been lobbed at idealism before, and I don’t think either one is compelling. The real oddity of Psillos’s view is the notion that idealism would need an external agent. If anything, ontological idealism already posits a fundamentally agentive universe, and so nothing extra is needed. In contrast, materialism still has to deal with the fine-tuning problem.