which must already 'be' before any other ways in which Being is determined, so that these can 'be' what they are. Extension must be 'assigned' ["zugewiesen"] primarily to the corporeal Thing. The 'world's' extension and substantiality (which itself is characterized by extension) are accordingly demonstrated by showing how all the other characteristics which this substance definitely possesses (especially divisio, figura, motus), can be conceived only as modi of extensio, while, on the other hand, extensio sine figura vel motu remains quite intelligible.

Thus a corporeal Thing that maintains its total extension can still undergo many changes in the ways in which that extension is distributed in the various dimensions, and can present itself in manifold shapes as one and the same Thing. " ... atque unum et idem corpus, retinerulo suam eandem quantitatem, pluribus diversis modis potest extendi: nunc scilicet magis secundum longitudinem, minusque secundum latitudinem vel profunditatem, ac paulo post e contra magis secundum latitudinem, et minus secundum longitudinem. "^vi

Shape is a modus of extensio, and so is motion: for motus is grasped only "si de nullo nisi locali cogitemus, ac de vi a qua excitatur ... non inquiramus."^vii If the motion is a property of the res corporea, and a property which i s, then in order for it to be experienceable in its Being, it must be conceived in terms of the Being of this entity itself, in terms of extensio; this means that it must be conceived as mere change of location. So nothing like 'force' counts for anything in determining what the Being of this entity is. Matter may have such definite characteristics as hardness, weight, and colour; (durities, pondus, color) ; but these can all be taken away from it, and it still remains what it is. These do not go to make up its real Being ; and in so far as they are, they turn out to be modes of extensio. Descartes tries to show this in detail with regard to 'hardness': " Nam, quantum ad duritiem, nihil aliud de illa sensus nobis indicat, quam partes durorum corporum resistere motui manuum nostrarum, cum in illas incurrant. Si enim, quotiescunque manus nostrae versus aliquam partem moventur, corpora omnia ibi existentia recederent eadem celeritate qua illae accedunt, nullam unquam duritiem sentiremus. Nee ullo modo potest intelligi, corpora quae sic recederent, idcirco naturam corporis esse amissura ; nee proinde ipsa in duritie consistit. "^viii Hardness is experienced when one feels one's way by touch [Tasten]. What does the sense of touch 'tell' us about it ? The parts of the hard Thing 'resist' a movement of the hand, such as an attempt to push it away. If, however, hard bodies, those which do not give way, should change their locations with the same velocity as that of the hand which 'strikes at' them, nothing would ever get touched [Berühren], and hardness would not be experienced and would accordingly never be. But it is quite incomprehensible that bodies which give way with such velocity should thus forfeit any of their