We all tend to favor our own ideas, which is natural enough. They are, after all, in a sense our very own babies, the conceptions of our minds. But conception is possible in the thinking subject only because of the subject’s encounter with the world. Our ideas owe their existence, ultimately, to things outside and independent of the mind, to which they refer: objective facts.
Our ideas are clear, and our understanding of them is clear, only to the extent that we keep constant tabs on the things to which they refer. The focus must always be on the originating sources of our ideas in the objective world. We do not really understand our own ideas if we suppose them to be self-generating, that is, not owing their existence to extramental realities.
The more we focus on our ideas in a way that systematically ignores their objective origins, the more unreliable those ideas become. The healthy bonds that bind together the subjective and objective orders are put under great strain, and if we push the process too far, the bonds may break. Then we have effectively divorced ourselves from the objective world. Instead of seeing the world as it is, we see a projected world, one that is not presented to our minds but which is the product of our minds.
When we speak of “establishing a fact,” we do not refer to establishing the existence of an idea in the mind. The idea in the mind, as we have seen, is a subjective fact, but the kind of fact we are concerned with establishing is an objective fact. To do so, we must look beyond our ideas to their sources in the objective world. I establish a fact if I successfully ascertain that there is, for a particular idea I have in mind, a corresponding reality external to my mind. For instance, I have a particular idea in my mind, which I label “cat.” Corresponding to that idea are actually existing things in the extramental world called “cats.” But I could have another idea in my mind, which I label “centaur” but for which no corresponding fact can be found in the extramental world. For all that, the idea of “centaur” is a subjective fact, since it really exists as an idea in my mind.