 there's no room in the physical world for objects. Objects exist, and I think the physical world exists, but objects are not part of the physical world. Take this humble object, it happens to be a book I've recently written, square one the foundations of knowledge. Sure looks like this is an object in space, doesn't it? Let me ask you, is this particular object constructed by a bunch of bits of matter? Are there constituent parts to this book? I think the answer is obvious. Yes, it has pages, it's got a cover, it's got a back, even the pages themselves have a bunch of constituent parts in them. They're made up of little bits of paper, those little bits of paper are made up of atoms, all the way down to the base units of physical reality, let's call them plank units. So there's a bunch of physical stuff here, a bunch of physical bits, but does the book exist in addition to the bits which constitute the book? If the book exists and the book is physical and all the constituent parts exist, that means the book somehow takes up space in addition to the space that's taken up by the constituent parts of the book. That somehow in the physical world you have all the constituent parts that take up all the space and then there's this additional thing which is the book. Now it gets even weirder if we say yes the physical book exists, but it doesn't take up space. Okay so that implies that somehow there is such a thing as a physical object that takes up no space? What exactly is that? What if there's a third option? What if we say yes the book exists but its entire existence is identical with all of the constituent particles that are arranged that particular way? Well then we run into this problem. What happens when I scratch the book and I remove a handful of very small constituent particles? Is this the same book? If it's the same book then somehow the particles have changed and yet it remains the same thing which would contradict what we previously said that the book is identical with the constituent particles. So if the book is identical with its constituent particles then I just changed the book and in fact the book from this second to this second has changed because at the microscopic level particles are moving here and then there. So the book only exists in one instant of time and after every instant it's constantly changing so now instead of thinking there's one book we have a gigantic incomprehensible amount of books that are all different from one another. So there's an easy way to resolve this problem if we recognize that okay if the book is constituted by constituent particles all of which take up space how could the book then in addition take up space? Well the way to resolve it is to say the book exists but it's a concept in our minds and the physical particles exist. The constituent particles, yes they have some kind of physical existence I think that's a reasonable assertion but there is nothing in addition in the physical world to the constituent particles. So the boundaries that we place around this grouping of constituent particles is entirely conceptual and it doesn't matter if I scratch it it's still because it's a concept it's still the same book. The particles could change I can probably rip out a few pages I can change the assortment I could print it on some other thing on some other material and it would still remain the same book because the book is conceptual not physical. Now again I'm not saying the physical world doesn't exist I'm saying the physical world does exist it is constituted by a bunch of base units of reality and we are the ones that populate the world with boundaries and with objects. Now usually this kind of language doesn't matter I mean we everybody walks around talking about objects and it works to think that this is some independent book out there in the world that language works but if you want to be super precise and super rigorous and have a clear metaphysical worldview we have to understand that what exists are parts and our mind assembles those parts into the whole.