limits, they say, are rigid and absolute: it reigns only in the field of phenomena, including the “outer” or physical world of the external senses, and the “inner” or psychical world open to mental experience, otherwise called “inner sense.”
The distinction here implied is so very important that I shall surely be pardoned for going far enough into the explanation of philosophical technicalities to make it clear. It is the distinction between (1) the facts of direct experience — the realities that present themselves to our sensible apprehension, “outer” or “inner” as the case may be, forming a series of innumerable items arranged either by contiguity in Space or by succession in Time — and (2) a higher or profounder kind of reality which reason requires us to assume as the indispensable and sufficient ground for the occurrence and the ceaseless changing of the former, and, above all, for those changeless connexions of sequence and position which we observe among them, and which by common consent we designate as the laws of cause and effect, or of the uniformity of Nature. To mark the fact that the realities of the first sort are without other evidence than their presentation to our senses “outer” or “inner,” it is agreed in philosophy to call them “phenomena,” that is, simply appearances in consciousness. To mark the counter-fact that the underlying Reality contrasted with appearances,
