Having thus freed intuitive knowledge from any suggestion of intellectualism and from every later and external addition, we must now explain it and determine its limits from another side and defend it from a different kind of invasion and confusion. On the hither side of the lower limit is sensation, formless matter, which the spirit can never apprehend in itself as simple matter. This it can only possess with form and in form, but postulates the notion of it as a mere limit. Matter, in its abstraction, is mechanism, passivity; it is what the spirit of man suffers, but does not produce. Without it no human knowledge or activity is possible; but mere matter produces animality, whatever is brutal and impulsive in man, not the spiritual dominion, which is humanity. How often we strive to understand clearly what is passing within us! We do catch a glimpse of something, but this does not appear to the mind as objectified and formed. It is in such moments as these that we best perceive the profound difference between matter and form. These are not two acts of ours, opposed to one another; but the one is outside us and assaults and sweeps us off our feet, while the other inside us tends to absorb and identify itself with that which is outside. Matter, clothed and conquered by form, produces concrete form. It is the matter, the content, which differentiates one of our intuitions from another: the form is constant: it is spiritual activity, while matter is changeable. Without matter spiritual activity would not forsake its abstractness to become concrete and real activity, this or that spiritual content, this or that definite intuition. It is a curious fact, characteristic of our times, that this very form, this very activity of the spirit, which is essentially ourselves, is so often ignored or denied. Some confound the spiritual activity of man with the metaphorical and mythological activity of what is called nature, which is mechanism and has no resemblance to human activity, save when we imagine, with Æsop, that "_arbores loquuntur non tantum ferae._" Some affirm that they have never observed in themselves this "miraculous" activity, as though there were no difference, or only one of quantity, between sweating and thinking, feeling cold and the energy of the will. Others, certainly with greater reason, would unify activity and mechanism in a more general concept, though they are specifically distinct. Let us, however, refrain for the moment from examining if such a final unification be possible, and in what sense, but admitting that the attempt may be made, it is clear that to unify two concepts in a third implies to begin with the admission of a difference between the two first. Here it is this difference that concerns us and we set it in relief. [Sidenote: _Intuition and association._]