To suppose that I could not is absurd: and if I can stretch it out, that which is outside must be either body or space (it makes no difference which it is as we shall see).

Please remove spaces between words.
TosupposethatIcouldnotisabsurd:andifIcanstretchitout,thatwhichisoutsidemustbeeitherbodyorspace(itmakesnodifferencewhichitisasweshallsee).