essential to Matter, &c. ZL

ly absurd, and suppose one thing, itself cau£ed or moved, the cause of another thing mov-*ed, in infinitum , which includes in it all thecontradictian of the Epicurean scheme); Isay, we must as much seek a cause ab extrato it, of its motion, as of the motion of thosebodies we are acquainted with, and have rea-soned from: so that we are removed butone step from the immaterial cause we werelooking for; and the conclusion above is se-cured, allowing the thing supposed here couldbe proved real. But then there are strongreasons that shew this hypothesis to be with-out foundation. Dr. s'Gravesande gives se-veral, which, I think, entirely overthrowit (/). One is, That the aElion as a fluid upon

a body

(i) I shall transcribe the whole paflage. It is in I. 4.c. 4. atN° 1237. XJlterius , Jigravitas pendeatd Uge mo~tus not a, ad impadum corporis extranet refetri debere , &quta gravitas e/l continua , impaffum etiam continuum re-qutri. Si talis materia cmtinuo in corpora impingens de-tur, nece/sarib eft Jluida, & quidemsubtilij/ima, qua pent.trat corpora quacunqut ; corpora cnim in aliis utcunque in-clusa gravta sunt. Videat nunc mathematicus , anfluidurtiadeb subtile, tit corporum omnium poros liberritne permeet ,its adeb rarum , ut motui corporum fenflbiliter non objlet ,(in loco tnim aere vacuo psnduli motus diutijfime continua -

tur)