inasmuch as it leaves out of view one of his most important phenomena. For, as the preceding case of A and B, so now in the case of A and A, there is developed the fact of A's observation of A. But this fact, which in the case of A and B was very properly overlooked, and was merely considered as the point to be looked from, cannot here be legitimately overlooked, but insists most peremptorily upon being made the point to be looked at; for the two A's are not really two, but one and the same; and, therefore, A's observation of the phenomena of A is itself a new phenomenon of A, calling for a new observation. Thus, while physical observation is simple, philosophical or psychological observation is double. It is observatio duplex: the observation of observation, observatio observationis. Now, we maintain that the disciples of the Baconian school have never recognised this distinction, or rather have never employed any other than the method of single observation, in studying the phenomena of man. They have been too eager to observe everything ever to have thought of duly observing the fact of observation itself. This phenomenon, by which everything else was brought under observation, was itself allowed an immunity from observation; and entirely to this laxness or neglect are, in our opinion, to be attributed all the errors that have vitiated, and all the obstructions that have retarded the science of ourselves.
The distinction which we have just pointed out
