See e.g. https://en.wikipedia.org/wiki/Finitism
Doron Zeilberger would like to pat you on the back.
Infinities have the opposite effect then you might think, they make things simpler. It's much easier to reason about an infinite list of numbers then to reason about 64 bit numbers.
In analysis, it's much easier to reason about infinitely differentiable, or smooth, surfaces then very rigid and complicated services.
The fact that infinities cause some complications in the foundations itself is a drop in the bucket to the practical application and simplifications of day to day mathematics.
I would argue that a few extra lines in a proof is a small price to pay to avoid the Godelian catastrophe.
A realist might say that mathematics exists within this universe, therefore it is equally subject to its constraints just like anything else. Problems arise via misapplication or misinterpretation of the math.
A model theorist might point out that even in models of math with only a countable collection of objects, it's still true that the reals are uncountable. The problem isn't with infinitie, it's that the finitary objects have subtle interactions.
A logician might object that ZFC already does start of with an intuitive notion of infinity, i.e. the counting numbers is a natural collection. The problem is that this inevitably has unintended consequences.
A historian might gently point out that this debate already occurred vigorously about 150 years ago, and the verdict was that we just gotta live with the weirdness of infinities. The problem is that we lose too much useful math by trying to throw them out.
Etc.
Note that I don't mean to imply that this is the entirety of my philosophy. Just that one should distinguish between what is practically relevant and what is not and I think the current state of mathematics and CS does a poor job of making this distinction.
He's very nearly a minority of one, mind you.
And you can't easily only partially include infinity.
> And you can't easily only partially include infinity.
Sure you can. You just need to use a dx that's small enough for the particular functions you're working with and the degree of precision you need.
One argument in favor of this belief is that neither practical computations nor analytic intuition require actual infinitesimals.
The later, at least, has been my experience. I think I have a fairly decent practical intuition for calculus based on imagining dx becoming smaller and smaller until it's small enough, but I don't think my brain has any actual representation of "true infinitesimals" and my intuition breaks down completely if I try to imagine things like the relationship between the rational and irrational numbers. Maybe that's due to my intellectual limitations, but I wonder if it isn't because these concepts might be over-elaborate abstractions that don't really exist in our world.
Don't derivatives count? That's a pretty important and trivial calculation. Sure, you can approximate it when it's nicely behaved, but they aren't always. There's also lots of verrrrrrry slowly converging series that can't be easily computed numerically.
And, again, coming up with derived theorems that are useful.
This is like Stacey King saying "I'll always remember this as the night that Michael Jordan and I combined for 70 points."
Pretty much the entire field of Analysis (of which calculus is a part) relies on 'infinities' of some kind. Even if you try to restrict to the rationals, you're still typically working with infinite series of them.
You can do some analysis over the rationals, but often this takes the form of Cauchy sequences of rationals which might be cheating.
[0] https://math.stackexchange.com/questions/387234/how-far-can-...