E3P49D
Demonstration — Part III
Latin
Res quam liberam esse imaginamur, debet (per definitionem 7 partis I) per se absque aliis percipi. Si igitur eandem lætitiæ vel tristitiæ causam esse imaginemur, eo ipso (per scholium propositionis 13 hujus) eandem amabimus vel odio habebimus idque (per propositionem præcedentem) summo amore vel odio qui ex dato affectu oriri potest. Sed si rem quæ ejusdem affectus est causa ut necessariam imaginemur, tum (per eandem definitionem 7 partis I) ipsam non solam sed cum aliis ejusdem affectus causam esse imaginabimur atque adeo (per propositionem præcedentem) amor et odium erga ipsam minor erit. Q.E.D.
English (Elwes 1883)
A thing which we conceive as free must (I. Def. vii.) be perceived through itself without anything else. If, therefore, we conceive it as the cause of pleasure or pain, we shall therefore (III. xiii. note) love it or hate it, and shall do so with the utmost love or hatred that can arise from the given emotion. But if the thing which causes the emotion be conceived as acting by necessity, we shall then (by the same Def. vii. Part I.) conceive it not as the sole cause, but as one of the causes of the emotion, and therefore our love or hatred towards it will be less. Q.E.D.
Modern English
A thing we conceive to be free must be perceived through itself without anything else (E1D7). If we therefore imagine it to be the cause of joy or sadness, we will for that reason love or hate it (E3P13S), and do so with the greatest love or hatred that can arise from the given affect. But if we conceive the thing that causes the affect as acting by necessity, we will then conceive it not as the sole cause but as one among other causes of the affect (E1D7), and so our love or hatred toward it will be less (E3P48). Q.E.D.