Philosophy Research on Time and Space – Update 2 on Space

Historical and current research on space has largely fallen on the relationship between objects and space, i.e. whether space is dependent on objects (there’s no space if there’s no object) or objects are dependent on space (there’s no object if there’s no space). Different from the concept of time, we cannot imagine anything without imagining it in space, and this gives space a special status.  Philosophy of science has done most of the work in contemporary philosophy, and that is not what my interest falls on. Therefore, my interest is primarily not about the relationship between objects and space, but the question: “what does it mean to be extended in space?”

This question of mine is inspired by the work of the Irish philosopher George Berkeley, who holds the view of subjective idealism, that everything we observed is just “ideas” in our mind, not real objects. He questions the concept “substratum” which John Locke brings up. Both philosophers are empiricists, believing that all of our knowledge comes from our experience. We observe objects by observing their properties: color, shape, textures, odor, etc. However, apart from what we can observe, is there anything else in an object? Locke defines substratum as something extended in space but without any properties, a thing that takes up space and is the object itself, but without any observable properties. Berkeley believes this substratum is absurd. Since Locke claims that substratum has no observable property, how could it have the property of extension?

I believe the problem lies on two aspects: whether extension is an observable property, and does it make sense to posit such a thing that cannot be observed. I believe the answer to the first question is no, so Berkeley’s objection does not work well, but through his question we see his real concern, i.e. the second question. Many people believe this world is physical. But we never observe this property of physicality. So why bother positing this property anyway? Relating to space, we seem to observe things in space, which seems to be extended. This seems to give us evidence that the world is physical, but does it really? So if space does not give us reason to believe in physicality and we do not observe the physicality of the world either, what reason do we have for believing that the world is physical? I think this is the real concern that we should have on philosophy of space.


  1. haoyukuan says:

    Hi Abe, I really love your summer research as this is my third comments on your research. I do believe the world is physical, as we have so many empirical indicators desgined by physicist to measure our world. You might argue that those empirical indicators are merely ideas and this actually falls into arguement of Berkeley, but to imagine the substratum itself is impossible. We are actually using our pre-defined knowledge, which we acquired from our past experiences based on a world where space itself is objectively measured, to imagine a subjective world.