"I have explained the causes of human infirmity and inconstancy, and shown why men do not abide by the precepts of reason. It now remains for me to show what course is marked out for us by reason, which of the emotions are in harmony with the rules of human reason, and which of them are contrary thereto. But, before I begin to prove my Propositions... it is advisable to sketch them briefly in advance... As reason makes no demands contrary to nature, it demands, that every man should love himself, should seek that which is useful to him... everything which really brings man to greater perfection... first, that the foundation of virtue is the endeavor to preserve one's own being, and... happiness consists in man's power of preserving his own being; secondly, that virtue is to be desired for its own sake, and that there is nothing more excellent or more useful to us... thirdly and lastly, that suicides are weak-minded, and are overcome by external causes repugnant to their nature. Further... we can never arrive at doing without all external things for the preservation of our being or living, so as to have no relations with things which are outside ourselves. ...our intellect would be more imperfect, if mind were alone, and could understand nothing besides itself. There are, then, many things outside ourselves, which are useful to us... none can be discerned more excellent, than those which are in entire agreement with our nature. ...if, for example, two individuals of entirely the same nature are united, they form a combination twice as powerful as either of them singly. Therefore, to man there is nothing more useful than man—nothing, I repeat, more excellent for preserving their being can be wished for by men, than that all should so in all points agree, that the minds and bodies of all should form, as it were, one single mind and one single body, and that all should, with one consent, as far as they are able, endeavor to preserve their being, and all with one consent seek what is useful to them all. Hence, men who are governed by reason—that is, who seek what is useful to them in accordance with reason, desire for themselves nothing, which they do not also desire for the rest of mankind, and, consequently, are just, faithful, and honorable in their conduct. ...I have taken this course, in order, if possible, to gain the attention of those who believe, that the principle that every man is bound to seek what is useful for himself is the foundation of impiety, rather than of piety and virtue."