14 A VIS INERTIAE

death and ruin are affected by the inactivityof moving matter. ‘Though matter then aSisupon matter by motion ; yet it is because of itsvery inaSiivity that it doth this.

XI. And farther, since matter resists mo-tion in any direction, or resists motion in alldirections equally, matter in motion will re-sist any change of direction. This is plainin all the possible cafes of the congress of bo-dies, or where they encounter each other intheir motions; for in all these cases they acton each other: and this action proceeds fromthe resistance they make to being put out ofthe direction they are moving in. That is,they resist a change of the direction of theirmotion. Whatever force matter hath to con-tinue in the state of motion it is in, it ex-erts it all, or a part of it at least, upon any

feu energiam Juam ad movendum deponere & per fe ad qui-etem redire , quampotejl figuram scmel Jibi induSlain exu-ere, & aliam recentem absque causa extrinseca acquirereAnd a little after: Non minor requiritur vis ad corporisalicujus motumsijhndum , quant prim necessariasuit ad e-undem motum carport imprimcndum: unde cum vis inertiaaqualibus mutationibus aqualiter semper rest flit ^ ilia nonminus efficax erit^ ut corpus in motu femelinceptoperseveres,qudrn ut corpus quiescens semper in eadem quietis Jlatupermanent.

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