The premise that space is an a priori condition of all human experience of the empirical world flows undisstilled from Kant [Critique of Pure Reason]. The skeptic's argument for idealism, that we cannot deduce that things are as they appear based on there appearance, is taken seriously. Kant's solution to the problem of an independent empirical reality is that we have a schema[0] for experiencing the world.
The gist of the argument is:
1. The idealist's argument assumes each of us experiences the world in the same way: as appearances.
2. Kant deduces the boundaries of our mechanism by distinguishing between inner experience parsed into a temporal schema and outer experience parsed into a spatial schema. The fact that we can talk about idealized space as geometry supports this claim without bogging down in a Platonic realm of Pure ideas.
3. The upside is that empirical knowledge if the external world is possible. The downside is that deductive knowledge of it is not. We cannot know the ding an sich.
It's a powerful enough abstraction that it actually disappears in modern culture to the point that people arguing against it will cite statistical or probabilistic evidence in making their case, i.e. arguing for an absolute truth based on a confidence interval.
[0]: "schema" as in a database analogy, not in the way Kant's argument is traditionally translated to English.
The gist of the argument is:
1. The idealist's argument assumes each of us experiences the world in the same way: as appearances.
2. Kant deduces the boundaries of our mechanism by distinguishing between inner experience parsed into a temporal schema and outer experience parsed into a spatial schema. The fact that we can talk about idealized space as geometry supports this claim without bogging down in a Platonic realm of Pure ideas.
3. The upside is that empirical knowledge if the external world is possible. The downside is that deductive knowledge of it is not. We cannot know the ding an sich.
It's a powerful enough abstraction that it actually disappears in modern culture to the point that people arguing against it will cite statistical or probabilistic evidence in making their case, i.e. arguing for an absolute truth based on a confidence interval.
[0]: "schema" as in a database analogy, not in the way Kant's argument is traditionally translated to English.