To assert that the categories taken by themselves are empty can scarcely be right, seeing that they have a content, at all events, in the special stamp and significance which they possess. Of course the content of the categories is not perceptible to the senses, nor is it in time and space: but that is rather a merit than a defect. A glimpse of this meaning of _content_ may be observed to affect our ordinary thinking. _A_ book or a speech for example is said to have a great deal in it, to be full of content, in proportion to the greater number of thoughts and general results to be found in it: whilst, on the contrary, we should never say that any book, _e.g._ novel, had much in it, because it included a great number of single incidents, situations, and the like. Even the popular voice thus recognises that something more than the facts of sense is needed to make a work pregnant with matter. And what is this additional desideratum but thoughts, or in the first instance the categories? And yet it is not altogether wrong, it should be added, to call the categories of themselves empty, if it be meant that they and the logical Idea, of which they are the members, do not constitute the whole of philosophy, but necessarily lead onwards in due progress to the real departments of Nature and Mind. Only let the progress not be misunderstood. The logical Ideal does not thereby come into possession of a content originally foreign to it: but by its own native action is specialised and developed to Nature and Mind. 44.] It follows that the categories are no fit terms to express the Absolute--the Absolute not being given in perception;--and Understanding, or knowledge by means of the categories, is consequently incapable of knowing the Things-in-themselves. The Thing-in-itself (and under 'thing' is embraced even Mind and God) expresses the object when we leave out of sight all that consciousness makes of it, all its emotional aspects, and all specific thoughts of it. It is easy to see what is left,--utter abstraction, total emptiness, only described still as an 'other-world'--the negative of every image, feeling, and definite thought. Nor does it require much penetration to see that this _caput mortuum_ is still only a product of thought, such as accrues when thought is carried on to abstraction unalloyed: that it is the work of the empty 'Ego,' which makes an object out of this empty self-identity of its own. The _negative_ characteristic which this abstract identity receives as an _object,_ is also enumerated among the categories of Kant, and is no less familiar than the empty identity aforesaid. Hence one can only read with surprise the perpetual remark that we do not know the Thing-in-itself. On the contrary there is nothing we can know so easily.