E4P21D
Demonstration — Part IV
Latin
Hujus propositionis demonstratio seu potius res ipsa per se patet et etiam ex cupiditatis definitione. Est enim cupiditas (per 1 affectuum definitionem) beate seu bene vivendi, agendi etc. ipsa hominis essentia hoc est (per propositionem 7 partis III) conatus quo unusquisque suum esse conservare conatur. Ergo nemo potest cupere etc. Q.E.D.
English (Elwes 1883)
The proof of this proposition, or rather the proposition itself, is self--evident, and is also plain from the definition of desire. For the desire of living, acting, &c., blessedly or rightly, is (Def. of the Emotions, i.) the essence of man--that is (III. vii.), the endeavour made by everyone to preserve his own being. Therefore, no one can desire, &c. Q.E.D.
Modern English
The demonstration of this proposition — or rather the thing itself — is self-evident, and also plain from the definition of desire. For desire (by the First Definition of the Affects (E3DA1)) is the very essence of a human being with respect to living well and acting well, that is (by P7 of Part III (E3P7)) the *conatus* by which each person strives to preserve their being. Therefore no one can desire, etc. Q.E.D.