 But our commonsense way of making the distinction soon goes by the wayside. Most philosophers wedded to some notion of acquaintance end up rejecting the idea that we have acquaintance even with bread-box sized objects, immediately before us, under ideal conditions of perception. The test to determine with what we are acquainted is often reminiscent of the method Descartes recommended for finding secure foundations of knowledge—the method of doubt (see Russell 1912: 74; Price 1932: 3). If you are considering whether you are acquainted with something, ask yourself whether you can conceive of being in this very state when the putative object does not exist. If you can, you should reject the suggestion that you are directly acquainted with the item in question. Based on possibilities of error about physical objects from illusion, hallucination and dreams, it seemed to most that we could rule out acquaintance with physical objects, future events, other minds, and facts that involve any of these as constituents. Consider, for example, physical objects. It seems that the evidence that my experiences give me right now for supposing that there is a computer before me is perfectly consistent with the hypothesis that I am now having a vivid dream or a vivid hallucination. If this is right, then the experiential evidence I possess cannot be the computer or any of its constituents. Neither the computer, nor any of its constituents, need be present in that vivid dream or hallucination. Even when our evidence for the presence of physical objects seems as good as we can get, then, we are not acquainted with physical objects or their constituents. (However, some have recently defended the view that we can be acquainted with physical objects in perception. See, for example, Johnston 2004.) Traditionally, acquaintance theorists have taken the most promising candidates for entities with which we can be acquainted to be conscious states of mind (e.g., an experience of pain, a sensation of red) and their properties (e.g., painfulness, redness). Russell and many other acquaintance theorists also take themselves to be acquainted with facts, i.e., with something’s having some property—at least mental facts (e.g., my being in pain, my desiring food, my experiencing red). 