Copied from wiki:
"Every composite material object is made up of elementary particles, and the only such composite objects are living organisms. A consequence of this view is that everyday objects such as tables, chairs, cars, buildings, and clouds do not exist. While there seem to be such things, this is only because there are elementary particles arranged in specific ways. For example, where it seems that there is a chair, Van Inwagen says that there are only elementary particles arranged chairwise."