ABSTRACT
We shall now turn to another set of idealist arguments, those based on our alleged inability to justify the belief in physical objects in a sense in which the latter term denotes objects possessing spatial characteristics that exist even when unperceived by us and is not analysable merely in terms of our experience or of what we actually perceive or would perceive under given circumstances. These arguments differ from those which have been discussed under the heading of epistemological arguments in that they are not drawn from a consideration of knowledge in general but from the particular problem of knowledge (or opinion) concerning physical objects. They do not assume any particular answer to the problem as to the nature of knowing and the relation between knowing and the known object, but simply maintain the impossibility of justifying on the available evidence a particular set of propositions which fall for realists within the realm of knowledge or justified opinion. The arguments do not belong to epistemology, though in their discussion, as in the discussion of any other philosophical problem, epistemological questions may have to be raised by us.
