47.2. The theory of space and time which we have thus reached is, of course, not complete; for completeness there is lacking a discussion of this second spatial and temporal (formative) relation of extension, or better, (to distinguish from the use of the term extension in the sense defined at the beginning of this essay) space and time magnitude, depending on the concept of distance and forming the basis of measurement and metric discussion upon which we have touched above in passing, but which is not to form a part of the present essay; we hope to devote to it a new study to which the present will form, as it were, an introduction. The method which must be followed in this development we shall indicate in the remaining few paragraphs.
48. It may appear that the conclusions reached in the above paragraphs are of little value, since they are valid for the time and space of a single mind, whereas different minds may arrive at a different ordering of the elements of their Experience, and thus render impossible any conclusions as to the space and time of the external world, which may be entirely different from the space and time of individual Experiences. That is, I think, an error arising from the mistaken judgment that the external world is given as an unordered aggregate of elements of Experience which individual minds first reduce to order, thus creating the space and time of their Experience. In reality the process is the reverse; the external world is given to minds as a whole, a coherent and connected structure of events, in which individual minds first seek out elements of Experience and their ordering; and whatever the metaphysical character of the external world—whether it is the work of some transcendent being acting upon a mind of the same structure, or whether it is some common creation of the human subconsciousness— the “Form” of the world is already there when it is presented to us in perception. Since, then, we have defined the external world as that part of the perceptual content of the mind which is common to all minds, and since the uniform ordering of its elements in every experience is the fundamental condition upon which part of Experience can be held in common by different minds (if the elements of Experience only, but not their ordering, were common to different minds, it would be impossible to decide whether anything was common to them at all), we can affirm as an axiom the principle, that the Form of Experience will be common to all minds and therefore a property of the external world independent of the individual mind; from this we can affirm a priori that two observers will agree in their “situational” description of phenomena (that is, a description which is
