Mr. Russell gives a specific illustration of what he takes to be the correct way of stating the question in an account of what, in the common-sense universe of discourse, would be termed walking around a table. If we exclude considerations to which we have (apart from assuming just the things which are doubtful) no right, the datum turns out to be something to be stated as follows: "What is really known[66] is a correlation of muscular and other bodily sensations with changes in visual sensations" (p. 77). By "sensations" must be meant sensible objects, not mental events. This statement repeats the point already dealt with: "muscular," "visual," and "other bodily" are all terms which are indispensable and which also assume the very thing professedly brought into question: the external world as that was defined. "Really known" assumes both noting and belief, with whatever complex implications they may involve--implications which, for all that appears to the contrary, may be indefinitely complex, and which, by Mr. Russell's own statement, involve relationship to at least two other terms besides the datum. But in addition there appears the new term "correlation." I cannot avoid the conclusion that this term involves an _explicit_ acknowledgment of the external world. Note, in the first place, that the correlation in question is not simple: it is threefold, being a correlation of correlations. The "changes in visual sensations" (objects) must be correlated in a temporal continuum; the "muscular and other bodily sensations" (objects) must also constitute a connected series. One set of changes belongs to the serial class "visual"; the other set to the serial class "muscular." And these two classes sustain a point-to-point correspondence to each other--they are correlated. I am not raising the old question of how such complex correlations can be said to be either "given" or "known" in sense, though it is worth a passing notice that it was on account of this sort of phenomenon that Kant postulated his threefold intellectual synthesis of apprehension, reproduction, and recognition in conception; and that it is upon the basis of necessity for such correlations that the rationalists have always criticized sensationalist empiricism. Personally I agree that temporal and spatial qualities are quite as much given in experience as are particulars--in fact, as I have been trying to show, particulars can be identified _as_ particulars only in a relational complex. My point is rather (i) that any such given is already precisely what is meant by the "world"; and (ii) that such a highly specified correlation as Mr. Russell here sets forth is in no case a psychological, or historical, primitive, but is a _logical_ primitive arrived at by an analysis of an empirical complex.