My third maxim was to endeavor always to conquer myself rather than fortune,and change my desires rather than the order of the world,and in general,accustom myself to the persuasion that,except our own thoughts,there is nothing absolutely in our power;so that when we have done our best in things external to us,all wherein we fail of success is to be held,as regards us,absolutely impossible:and this single principle seemed to me sufficient to prevent me from desiring for the future anything which I could not obtain,and thus render me contented;for since our will naturally seeks those objects alone which the understanding represents as in some way possible of attainment,it is plain,that if we consider all external goods as equally beyond our power,we shall no more regret the absence of such goods as seem due to our birth,when deprived of them without any fault of ours,than our not possessing the kingdoms of China or Mexico,and thus making,so to speak,a virtue of necessity,we shall no more desire health in disease,or freedom in imprisonment,than we now do bodies incorruptible as diamonds,or the wings of birds to fly with.But I confess there is need of prolonged discipline and frequently repeated meditation to accustom the mind to view all objects in this light;and I believe that in this chiefly consisted the secret of the power of such philosophers as in former times were enabled to rise superior to the influence of fortune,and,amid suffering and poverty,enjoy a happiness which their gods might have envied.For,occupied incessantly with the consideration of the limits prescribed to their power by nature,they became so entirely convinced that nothing was at their disposal except their own thoughts,that this conviction was of itself sufficient to prevent their entertaining any desire of other objects;and over their thoughts they acquired a sway so absolute,that they had some ground on this account for esteeming themselves more rich and more powerful,more free and more happy,than other men who,whatever be the favors heaped on them by nature and fortune,if destitute of this philosophy,can never command the realization of all their desires.
In fine,to conclude this code of morals,I thought of reviewing the different occupations of men in this life,with the view of making choice of the best.And,without wishing to offer any remarks on the employments of others,I may state that it was my conviction that I could not do better than continue in that in which I was engaged,viz.,in devoting my whole life to the culture of my reason,and in making the greatest progress I was able in the knowledge of truth,on the principles of the method which I had prescribed to myself.This method,from the time I had begun to apply it,had been to me the source of satisfaction so intense as to lead me to,believe that more perfect or more innocent could not be enjoyed in this life;and as by its means I daily discovered truths that appeared to me of some importance,and of which other men were generally ignorant,the gratification thence arising so occupied my mind that I was wholly indifferent to every other object.Besides,the three preceding maxims were founded singly on the design of continuing the work of self-instruction.For since God has endowed each of us with some light of reason by which to distinguish truth from error,I could not have believed that I ought for a single moment to rest satisfied with the opinions of another,unless I had resolved to exercise my own judgment in examining these whenever I should be duly qualified for the task.Nor could I have proceeded on such opinions without scruple,had I supposed that I should thereby forfeit any advantage for attaining still more accurate,should such exist.And,in fine,I could not have restrained my desires,nor remained satisfied had I not followed a path in which I thought myself certain of attaining all the knowledge to the acquisition of which I was competent,as well as the largest amount of what is truly good which Icould ever hope to secure Inasmuch as we neither seek nor shun any object except in so far as our understanding represents it as good or bad,all that is necessary to right action is right judgment,and to the best action the most correct judgment,that is,to the acquisition of all the virtues with all else that is truly valuable and within our reach;and the assurance of such an acquisition cannot fail to render us contented.