question is by sticking in the most uncompromising fashion to _that_ experience as real. _That_ experience is that two lines with certain cross-hatchings are apprehended as convergent; only by taking that experience as real and as fully real, is there any basis for, or way of going to, an experienced knowledge that the lines are parallel. It is in the concrete thing _as experienced_ that all the grounds and clues to its own intellectual or logical rectification are contained. It is because this thing, afterwards adjudged false, is a concrete _that_, that it develops into a corrected experience (that is, experience of a corrected thing--we reform things just as we reform ourselves or a bad boy) whose full content is not a whit more real, but which is true or truer.[52] If _any_ experience, then a _determinate_ experience; and this determinateness is the only, and is the adequate, principle of control, or “objectivity.” The experience may be of the vaguest sort. I may not see anything which I can identify as a familiar object--a table, a chair, etc. It may be dark; I may have only the vaguest impression that there is something which looks like a table. Or I may be completely befogged and confused, as when one rises quickly from sleep in a pitch-dark room. But this vagueness, this doubtfulness, this confusion is the thing experienced, and, _qua_ real, is as “good” a reality as the self-luminous vision of an Absolute. It is not just vagueness, doubtfulness, confusion, at large or in general. It is _this_ vagueness, and no other; absolutely unique, absolutely what _it_ is.[53] Whatever gain in clearness, in fullness, in trueness of content is experienced must grow out of some element in the experience of _this_ experienced _as_ what it is. To return to the illusion: If the experience of the lines as convergent is illusory, it is because of some elements in the thing as experienced, not because of something defined in terms of externality to this particular experience. If the illusoriness can be detected, it is because the thing experienced is real, having within its experienced reality elements whose _own mutual_ tension effects its reconstruction. Taken concretely, the experience of convergent lines contains within itself the elements of the transformation of its own content. It is _this_ thing, and not some separate truth, that clamors for its own reform. There is, then, from the empiricist’s point of view, no need to search for some aboriginal _that_ to which all successive experiences are attached, and which is somehow thereby undergoing continuous change. Experience is always of _thats_; and the most comprehensive and inclusive experience of the universe that the philosopher himself can obtain is the experience of a characteristic _that_. From the empiricist’s point of view, this is as true of the exhaustive and complete insight of a hypothetical all-knower as of the vague, blind experience of the awakened sleeper.