>>>>>Proof--That which we love we endeavour, as far as we can, to conceive in preference to anything else (III. xii.). If the thing be similar to ourselves, we shall endeavour to affect it pleasurably in preference to anything else (III. xxix.). In other words, we shall endeavour, as far as we can, to bring it about, that the thing should be affected with pleasure accompanied by the idea of ourselves, that is (III. xiii. note), that it should love us in return. Q.E.D. XXXIV. The greater the emotion with which we conceive a loved object to be affected towards us, the greater will be our complacency. >>>>>Proof--We endeavour (III. xxxiii.), as far as we can, to bring about, that what we love should love us in return: in other words, that what we love should be affected with pleasure accompanied by the idea of ourself as cause. Therefore, in proportion as the loved object is more pleasurably affected because of us, our endeavour will be assisted. --that is (III. xi. and note) the greater will be our pleasure. But when we take pleasure in the fact, that we pleasurably affect something similar to ourselves, we regard ourselves with pleasure (III. xxx); therefore the greater the emotion with which we conceive a loved object to be affected, &c. Q.E.D. XXXV. If anyone conceives, that an object of his love joins itself to another with closer bonds of friendship than he himself has attained to, he will be affected with hatred towards the loved object and with envy towards his rival. >>>>>Proof--In proportion as a man thinks, that a loved object is well affected towards him, will be the strength of his self-approval (by the last Prop.), that is (III. xxx. note), of his pleasure; he will, therefore (III. xxviii.), endeavour, as far as he can, to imagine the loved object as most closely bound to him: this endeavour or desire will be increased, if he thinks that someone else has a similar desire (III. xxxi.). But this endeavour or desire is assumed to be checked by the image of the loved object in conjunction with the image of him whom the loved object has joined to itself; therefore (III. xi. note) he will for that reason be affected with pain, accompanied by the idea of the loved object as a cause in conjunction with the image of his rival; that is, he will be (III. xiii.) affected with hatred towards the loved object and also towards his rival (III. xv. Cor.), which latter he will envy as enjoying the beloved object. Q.E.D.