Relevant, by @HaydnBelfield:
There is ambiguity in the terminology here. So here is how I visualize it with my own terminology. Its not a Venn diagram but this is how I see it.
I interpret this as using different discount rates (specifically, pure time preference, to distinguish from discounting for marginal utility or exogenous extinction risk). Is that right? That is, temporal radicalists have pure time preference = 0, while the others have pure time preference > 0.
Or do you mean something else by "how long into the future you're willing to look"?