I am in doubt as to the propriety of making my first meditations in the place above mentioned matter of discourse;for these are so metaphysical,and so uncommon,as not,perhaps,to be acceptable to every one.And yet,that it may be determined whether the foundations that I have laid are sufficiently secure,I find myself in a measure constrained to advert to them.I had long before remarked that,in relation to practice,it is sometimes necessary to adopt,as if above doubt,opinions which we discern to be highly uncertain,as has been already said;but as I then desired to give my attention solely to the search after truth,I thought that a procedure exactly the opposite was called for,and that I ought to reject as absolutely false all opinions in regard to which I could suppose the least ground for doubt,in order to ascertain whether after that there remained aught in my belief that was wholly indubitable.Accordingly,seeing that our senses sometimes deceive us,I was willing to suppose that there existed nothing really such as they presented to us;and because some men err in reasoning,and fall into paralogisms,even on the simplest matters of geometry,I,convinced that I was as open to error as any other,rejected as false all the reasonings I had hitherto taken for demonstrations;and finally,when I considered that the very same thoughts (presentations)which we experience when awake may also be experienced when we are asleep,while there is at that time not one of them true,Isupposed that all the objects (presentations)that had ever entered into my mind when awake,had in them no more truth than the illusions of my dreams.But immediately upon this I observed that,whilst I thus wished to think that all was false,it was absolutely necessary that I,who thus thought,should be somewhat;and as I observed that this truth,I think,therefore I am (COGITO ERGO SUM),was so certain and of such evidence that no ground of doubt,however extravagant,could be alleged by the sceptics capable of shaking it,I concluded that I might,without scruple,accept it as the first principle of the philosophy of which I was in search In the next place,I attentively examined what I was and as I observed that I could suppose that I had no body,and that there was no world nor any place in which I might be;but that I could not therefore suppose that I was not;and that,on the contrary,from the very circumstance that Ithought to doubt of the truth of other things,it most clearly and certainly followed that I was;while,on the other hand,if I had only ceased to think,although all the other objects which I had ever imagined had been in reality existent,I would have had no reason to believe that Iexisted;I thence concluded that I was a substance whose whole essence or nature consists only in thinking,and which,that it may exist,has need of no place,nor is dependent on any material thing;so that "I,"that is to say,the mind by which I am what I am,is wholly distinct from the body,and is even more easily known than the latter,and is such,that although the latter were not,it would still continue to be all that it is.
After this I inquired in general into what is essential I to the truth and certainty of a proposition;for since I had discovered one which I knew to be true,I thought that I must likewise be able to discover the ground of this certitude.And as I observed that in the words I think,therefore Iam,there is nothing at all which gives me assurance of their truth beyond this,that I see very clearly that in order to think it is necessary to exist,I concluded that I might take,as a general rule,the principle,that all the things which we very clearly and distinctly conceive are true,only observing,however,that there is some difficulty in rightly determining the objects which we distinctly conceive.
In the next place,from reflecting on the circumstance that I doubted,and that consequently my being was not wholly perfect (for I clearly saw that it was a greater perfection to know than to doubt),I was led to inquire whence I had learned to think of something more perfect than myself;and Iclearly recognized that I must hold this notion from some nature which in reality was more perfect.As for the thoughts of many other objects external to me,as of the sky,the earth,light,heat,and a thousand more,I was less at a loss to know whence these came;for since I remarked in them nothing which seemed to render them superior to myself,I could believe that,if these were true,they were dependencies on my own nature,in so far as it possessed a certain perfection,and,if they were false,that I held them from nothing,that is to say,that they were in me because of a certain imperfection of my nature.But this could not be the case with-the idea of a nature more perfect than myself;for to receive it from nothing was a thing manifestly impossible;and,because it is not less repugnant that the more perfect should be an effect of,and dependence on the less perfect,than that something should proceed from nothing,it was equally impossible that I could hold it from myself:accordingly,it but remained that it had been placed in me by a nature which was in reality more perfect than mine,and which even possessed within itself all the perfections of which I could form any idea;that is to say,in a single word,which was God.
