Bundle theory
The bundle theory, a theory in metaphysics and ontology about objecthood, is the view that an object is a bundle, or collection, of properties. Hence, one cannot even conceive of a propertyless object: the object just is its properties, and so if you take away its properties you take away the object itself.
To illustrate, think of an apple, but do not think of its color, of its shape, of the fact that it is a kind of fruit, of the cells that it's made of, of its taste, and so on. Think of the apple, but do not think of any of its properties. Is that possible? The bundle theorist says it is not possible. So the apple is no more than a collection of properties. There isn't any more to the apple than that. In particular, there is no "substance" that these properties inhere in.
Arguments for the bundle theory
The most common sort of argument for the bundle theory capitalizes on the above insights. The basic idea is that however we might choose to conceive of, or describe a thing, it will be a conception, or a description, of a property of a thing. In other words, there is nothing that can be described, or even conceived, about a thing, which is not a property of the thing. (Or a relation of the thing, but we can ignore relations for simplicity's sake.) We cannot have the slightest idea of any aspect of the thing that is not a property of it.
This implies, the bundle theorist maintains, that we cannot have any conception whatsoever of a "bare particular." As the English philosopher John Locke said, a substance by itself, apart from its properties, is "something, I know not what." The only way that we can conceive of an object is by conceiving of its properties.
Therefore, the bundle theorist concludes, to conceive of an object just is to conceive of a bundle of properties. The only conception we can have of an object is as a bundle of properties. The bundle theory wins out, on this view, simply because it is the only game in town: the only way we can conceive of things is as bundles of properties. We could not imagine a bare particular, a propertyless substance, even if we tried. So the bundle theory is correct and the substance theory is wrong.
Many philosophers in the
