And now, I suddenly shut myself out of this world of perceptions and imaginations, or rather I keep them all before me, but not because of the immediate, individual interest I have in each of them. I try to extract the common, the universal element of which I suspect the existence not beyond but within them. I renounce all particular intuitions for the concept of intuition. I am no longer an image-making mind, no longer engaged in this elementary or "first" operation of the human mind, but I have passed on to a different, and manifestly a "secondary" plane of mental activity, since it would be impossible for me to root my thinking anywhere but on the soil of my intuitions. What, then, is intuition? Clearly it is not the mere sensation, the formless matter which the mind cannot grasp in itself, as mere matter, but possesses only by imposing its form on it. Without matter no human knowledge or activity is possible, but matter is, within ourselves, the animal element, that which is brutal and impulsive, not the spiritual domain, which is humanity. Matter conquered by form gives place to the concrete form. Matter, or content, is what differentiates one intuition from another; the form is constant, and the form is the spiritual activity. In this way we set the lower limit of intuitive knowledge, and we recognize its characters of awareness and activity: an intuition is not that which presents itself to me, but that which I make my own, by giving form to it. It may be an actual perception, but the distinction between that which is real and that which is imaginary is not an intuitive, but a logical or intellectual one; the knowledge of things which I do not perceive, but only remember, or even only create with my imagination belongs to the same class, partakes of the same formal character. Space and time, which have more than once been considered as intuitions, are in reality categories of an intellectual order: they may be found in intuitions, as other intellectual elements are found, but as ingredients and not as necessary elements, _materialiter_ and not _formaliter_. In relation to the usual psychological concepts of association and representation, it can be said that an intuition is an association, when by that word we mean an active mental synthesis, and not a mechanical juxtaposition of abstract sensations; and that it is a representation, not as a complex sensation, but as a spiritual elaboration of the sensation.