In so far as we imagine an object as contingent, we are affected with no image of any other object which posits the existence of the first. On the contrary, we imagine (by hypothesis) certain things which exclude its present existence. But in so far as we imagine it in relationship to past time are we supposed to imagine something which brings it back to the memory or which excites its image and therefore so far causes us to contemplate it as present. Therefore, the emotion towards a contingent object which we know does not exist in the present, other things being equal, will be weaker than the emotion towards a past object. In these propositions I consider that I have explained why men are more strongly influenced by an opinion than by true reason, and why the true knowledge of good and evil causes disturbance in the mind, and often gives way to every kind of lust, whence the saying of the poet, "_Video meliora proboque, deteriora sequor._" The same thought appears to have been in the mind of the Preacher when he said, "_He that increaseth knowledge increaseth sorrow._" I say these things not because I would be understood to conclude, therefore, that it is better to be ignorant than to be wise, or that the wise man in governing his passions is nothing better than the fool, but I say them because it is necessary for us to know both the strength and weakness of our nature, so that we may determine what reason can do and what it cannot do in governing our emotions. FOOTNOTES: [29] Chapter Eight _ad fin._ CHAPTER XV THE FOUNDATIONS OF THE MORAL LIFE _Introductory_ I have briefly explained the causes of human impotence and want of stability, and why men do not obey the dictates of reason. It remains for me now to show what it is which reason prescribes to us, which emotions agree with the rules of human reason, and which, on the contrary, are opposed to these rules. Before, however, I begin to demonstrate these things by our full method, I should like briefly to set forth here these dictates of reason, in order that what I have in my mind about them may be easily comprehended by all.