商标论证
Outline of Descartes' argument

My ideas may be innate, adventitious (i.e. come from outside me), or have been invented by me. As yet I don't know their true origin.
If ideas are considered simply as modes of thought, they are all equal and appear to come from within me; in so far as different ideas represent different things they differ widely. Ideas which represent substances contain within themselves more objective reality than the ideas which merely represent modes; the idea that gives me my understanding of a supreme God, (eternal, infinite, etc.) has more objective reality than the ideas that represent finite substances.
It is manifest by the natural light that there must be at least as much reality in the efficient and total cause as in the effect of that cause.
It follows from this both that something cannot arise from nothing, and also that what contains more reality cannot arise from what contains less reality. And this applies not only when considering formal reality, but also when considering objective reality.
Although the reality in my ideas is merely objective reality what ultimately causes those ideas must contain the same formal reality. Although one idea may originate from another, there cannot be an infinite regress here; eventually one must reach a primary idea, the cause of which will contain formally all the reality which is present only objectively in the idea.
Ideas are like pictures which can easily fall short of the perfection of the things from which they are taken, but which cannot contain anything greater or more perfect.
If the objective reality of any of my ideas turns out to be so great that I am sure the same reality does not reside in me, either formally or eminently (i.e. potentially), and hence that I myself cannot be its cause, it will necessarily follow that I am not alone in the world, but that some other thing which is the cause of this idea also exists.
In addition to being aware of myself, I have other ideas— of God, corporeal and inanimate things, angels, animals and other men like myself. Except for the idea of God, it doesn't seem impossible that these ideas originated from within myself.
By the word ‘God’ I understand a substance that is infinite, eternal, immutable, etc. These attributes are such that it doesn't seem possible for them to have originated from me alone. So from what has been said it must be concluded that God necessarily exists.
Further considerations:
Although I have the idea of substance in me by virtue of being a substance, this does not account for my having the idea of an infinite substance, when I am finite. This idea must have come from some substance which really was infinite.
I cannot have gained the idea of the infinite merely by negating the finite. On the contrary, to know that I am finite means knowing that I lack something and so must first have the idea of the infinite to make that comparison.
The perfections which I attribute to God do not exist in me potentially. It is true that I have many potentialities which are not yet actual but this irrelevant to the idea of God, which contains absolutely nothing that is potential. It might be thought that my gradual increase in knowledge could continue to infinity but firstly, this gradual increase in knowledge is itself a sign of imperfection and, secondly, God I take to be actually infinite, so that nothing can be added to his perfection whereas increasing knowledge will never reach the point where it is not capable of a further increase. Finally, the objective being of an idea cannot be produced merely by potential being, which strictly speaking is nothing, but only by actual or formal being.
Additional argument for the existence of God:
I couldn't exist as the kind of thing that has this idea of God if God didn't exist, for I didn't create myself, I haven't always existed, and, although there may be a series of causes that led to my existence, the ultimate cause must be such that it could give me the idea of God and this, for the reasons already given, will be God.
This idea of God didn't come to me via the senses, nor did I invent this idea for I am plainly unable either to take away anything from it or to add anything to it. The only remaining alternative is that it is innate in me.