conjectures as to the reasons and the weaknesses which may have influenced Kant so to disfigure his immortal work, I have given in a letter to Professor Rosenkranz, and he has quoted the principal passage of it in his preface to the second volume of the edition of Kant’s collected works edited by him, to which I therefore refer. In consequence of my representations, Professor Rosenkranz was induced in the year 1838 to restore the “Critique of Pure Reason” to its original form, for in the second volume referred to he had it printed according to the _first_ edition of 1781, by which he has rendered an inestimable service to philosophy; indeed, he has perhaps saved from destruction the most important work of German literature; and this should always be remembered to his credit. But let no one imagine that he knows the “Critique of Pure Reason” and has a distinct conception of Kant’s teaching if he has only read the second or one of the later editions. That is altogether impossible, for he has only read a mutilated, spoilt, and to a certain extent ungenuine text. It is my duty to say this here decidedly and for every one’s warning. Yet the way in which Kant introduces the _thing in itself_ stands in undeniable contradiction with the distinctly idealistic point of view so clearly expressed in the first edition of the “Critique of Pure Reason,” and without doubt this is the chief reason why, in the second edition, he suppressed the principal idealistic passage we have referred to, and directly declared himself opposed to the Berkeleian idealism, though by doing so he only introduced inconsistencies into his work, without being able to remedy its principal defect. This defect, as is known, is the introduction of the _thing in itself_ in the way chosen by him, the inadmissibleness of which was exposed at length by G. E. Schulze in “_Ænesidemus_,” and was soon recognised as the untenable point of his system. The matter may be made clear in a very few words. Kant based the assumption of the thing in itself, though concealed under various modes of expression, upon an inference from the law of causality—an inference that the empirical perception, or more accurately the _sensation_, in our organs of sense, from which it proceeds, must have an external cause. But according to his own account, which is correct, the law of causality is known to us _a priori_, consequently is a function of our intellect, and is thus of _subjective_ origin; further, sensation itself, to which we here apply the law of causality, is undeniably _subjective_; and finally, even space, in which, by means of this application, we place the cause of this sensation as object, is a form of our intellect given _a priori_, and is consequently _subjective_. Therefore the whole empirical perception remains always upon a _subjective_ foundation, as a mere process in us, and nothing entirely different from it and independent of it can be