> I think a lot of people, especially in STEM, pooh-pooh philosophy at first.
A lot of philosophy ignores biology, sometimes even physics. In topics where biology would be immensely relevant, like with philosophy of mind. Dennett didn't try to ignore biology, he was deeply aware and well read in biology as well.
Most of the philosophy I'm familiar with is concerned with abstract notions and concepts like morality. I'm really having a hard time seeing how biology or physics would inform it one direction or another.
Like, what sort of biology would have made Kant's notions of morality different?
Kant used Newtonian assumptions about the time and space, treating them as absolute, and treating them not as properties of physics but necessary preconditions for us being able to experience anything.
Relativity overturned those Newtonian assumptions on which Kant depended, although he might say we nevertheless have to experience time as constant and space in three dimensions, regardless of how those things turn out to "really" work, since that's the only way we can do it.
So it's no longer obvious that time and space are just given absolutely, and due to that, they no longer make for a comfortable starting point for philosophical assumptions. If nature itself is different, then we might not even be experiencing it that way in the first place.
More tentatively, I think our advancing understanding of how brains and machines embody concepts, our understanding of the differences of biological creatures combined with new physics, is suggestive at a bare minimum that reality could be experienced differently, and/or that we can understand how we experience these things empirically with better knowledge about brains, instead of asserting that everything is governed at the outset by this or that philosophical assumption.
"Relativity overturned those Newtonian assumptions on which Kant depended, although he might say we nevertheless have to experience time as constant and space in three dimensions, regardless of how those things turn out to "really" work, since that's the only way we can do it."
I think you are more wrong than right here. My understanding (informed by Onora O'neill, Dan Bonevac, and various Stanford Encyclopedia entries :-)) is that Kant does not specifically depend on Newtonian assumptions but that human perceptions have to be mediated by time and space. Instead of overturning Kant, relativity and QM put even more distance between what we, as mortal, physical beings, can perceive versus whatever is really going on in the world.
Kant's project was to discover, given all of that, what anyone can say about things like ethics. He even goes so far to say that what he is trying to do is universal and he would like it to apply to other forms of intelligent beings.
> is that Kant does not specifically depend on Newtonian assumptions but that human perceptions have to be mediated by time and space
I understand the point about mediation, and I tried to speak to it directly in the portion you quoted. You are exactly right about the way Kant uses that in his argument. It's flexible enough that it can be understood as resilient, I think.
I tried show how science can nevertheless speak to it in several ways. One is the convenient equivalence between Kant's necessary conditions and nature as we understood it at the time. That equivalence makes it easier to be comfortable positing time and space as we understand them as necessary conditions that are prior to nature. It would be harder (but not impossible!) to entertain if there was daylight between what we believed our faculties to be and what we believed the natural world to be, if what was "necessary" was something different than what we thought we experienced (such as, say, a singular loaf of unified spacetime). An implication of Kant's view, as I understood him, was that we should be ready to believe it's different anyway, but nevertheless, it's easier to swallow when it perfectly aligns with how we thing the world really is.
Second, for a different way of stating a similar point, if time and space are non-newtonian in some important way, we may have to understand that that is what we experience in the first instance, and we would have to wrestle with the fact that our intuitions may attest to a variety of possible underlying necessary conditions. (Wittgenstein has been mentioned in this thread, so for a paraphrase of something he supposedly said, in reply to a student noting that it looks like the sun goes around the earth: "What would it look like if the earth went around the sun?" So it may be with the nature of our faculties.)
Third, as we gain deeper understanding of brain functions of ourselves and other creatures, we may have inroads to how certain of our conscious experiences depend on conceptual abstractions or models. And if so, it transforms it into an open empirical question rather than one where we are simply stuck presuming necessary conditions. Kant might insist that that is all already through the lense of our faculties such as they are, but we, with more information, would be increasingly comfortable just not entertaining them as we get increasingly robust empirical understandings of conscious experience.
None of these is a "defeater" argument by itself and there's a lot that can be talked about here of course, but I think given 21st century science, if Kant were trying to present his vision for the first time we might find it more challenging to reconcile with what we know of the natural world.
>Relativity overturned those Newtonian assumptions
Only in *very* specific situations which are extremely extremely extremely unrelated and WELL out of both practical and theoretical bound to the human perception of reality.
Relativity is kind of the trivia of physics, it really has not informed much technology apart from a few things in space - compare this to, say, quantum electrodynamics which tells us why weird stuff happens in things we've made quadrillions of (not to mention quantum computing, etc.)
The only time we would have ever brushed up against it naturally might have been when we put clocks into space so that we could better send nukes into other parts of the globe.
A beautiful way of putting it. I like this phrasing because I think it shows how progress in science actually elevated our confidence in Newtonian behaviors by having them as a special case of a theory with a stronger foundation.
I'm pretty sure you don't find any passage in Kant where he says anything remotely like "Gallilean/neo-Newtonian space-time is absolutely true and forever true" (these words or the term "Euclidean geometry" didn't, I'm pretty sure, even exist back then). What is usually meant by ascribing him these views, I assume, is that he proceeds as if this were the case, i.e. he doesn't specify any empirical method for determining what is the proper geometry of space-time. These were developed in the nineteenth century. But even remarkably smart people, like Poincare, had troubles with figuring out how empirical evidence can help determine us the physically valid geometry of space-time (he thought it was necessarily conventional - a view falsified by general relativity), so I don't think this in any way makes Kant's enterprise as such questionable.
I find it interesting that you say: "although he might say we nevertheless have to experience time as constant and space in three dimensions". The physicist/philosopher/physiologist/mathematician Hermann von Helmholtz (who was, I think, very much inspired by Kant) wanted to prove that, given some basic measurement axioms (demanding constant curvature etc.), Euclidean geometry is necessarily the geometry of our internal perceptual manifolds (Kant's view is, I believe, essentially that these internal manifolds must have the same geometry as physical space-time). But it turned out that pseudo-spherical geometry also satisfies these axioms. So, although there is something, as far as your general description goes, to your 'defence' of Kant, and I think Helmholtz himself would've said that he's working within Kant's framework, it is still insufficient to vindicate everything that Kant said. I believe Helmholtz agreed, however, that our spatial imagination is three dimensional.
What I mean by "Kant's framework" is basically these three theses:
1. There are internal perceptual manifolds, distinct from mind-independent space-time.
2. Space adn time are preconditions of experience as such, i.e. we cannot ever get rid of them in our description of the world. They're not reducible to causal relations between events.
3. This doesn't require assuming Newtonian absolute space (relativism).
And Kant furthermore asserts that:
4. In addition to (1), there is no mind-independent space-time, space and time as such are mind-dependent. This means that our descriptions of the world are necessarily, e.g. Euclidean.
I don't think (1), (2), (3) are at all controversial, although only (2) and its consequences are a contribution of Kant himself, but (4) is, I'm pretty sure, quite universally rejected nowadays.
It's true relativity was problematic for Kant's project (particularly re: his thought about Euclidean geometry), and you're right to point to this as an example of science informing philosophical thought.
My understanding is that post-relativity, Neokantians have been trying to reconcile Kant's thought with the implications of relativity. Philosophy as a discipline is, as I understand it, happy to work with new scientific discoveries, and not going to stick with philosophical dogma in the face of contradicting science. Besides, beyond a certain level, doesn't science have to give way to philosophy? I don't see holding certain philosophical assumptions (not really assumptions, but intuitions or propositions argued from intuitions) as a necessarily bad thing or even an avoidable thing, as long as it's open to both philosophical and scientific criticism, where applicable.
At the end of the day I think you're right that Kant's notion of necessary conditions is probably flexible enough to accommodate the findings of general relativity.
The fact that the relation is one of an amendment or a reconciliation to new data is a point in favor of skepticism against his original assumptions, but not a defeater.
I would agree that we can credit intuitions as being more than mere assumptions, and I think you're right about The legitimacy of positing assumptions as long as they're posited in a spirit of openness and responsiveness to philosophical and scientific criticism. What do you know, a healthy and reasonable of reply on philosophy. To tie this to Daniel Dennett, I have found one of his most valuable contributions to be a notion of the principle of charity, which is to credit the person you correspond with with the most reasonable possible interpretation, and I think the best philosophical exchanges are carried out in that spirit, and so I think he would highlight yours as the response in this thread that best embodies that principle.
I'm pretty sure there were already in the 19th century people, like Helmholtz, Riemann etc. who saw themselves as Kantians, but nevertheless developed many of the techniques that later made GR possible (while acknowledging that they challenge Kant's own views) while preserving the core of Kant's theory. See my response above.
> Kant used Newtonian assumptions about the time and space, treating them as absolute, and treating them not as properties of physics but necessary preconditions for us being able to experience anything.
Ok... this is non sequitur. It really doesn't matter that time moves at different speeds for any of Kant's philosophical positions. 2 people could be traveling at 0.5c and 0.00000001c and that makes no difference in Kant morals on how they should behave.
And, practically speaking, unless there's a drastic development in propulsion the only bearing relativity has on day to day life is making sure the GPS works correctly. It is, otherwise, completely non-impactful to anyone beyond astrophysicists.
>no difference in Kant morals on how they should behave.
This wasn't about Kant's morals. This was about the idea that Newtonian conceptions of space and time familiar to Kant were necessary preconditions to experience.
A lot of philosophy ignores biology, sometimes even physics. In topics where biology would be immensely relevant, like with philosophy of mind. Dennett didn't try to ignore biology, he was deeply aware and well read in biology as well.