2 IdeasI have noted before, even though the objects of my sensory experience and imagination may have no existence outside of me, nonetheless the modes of thinking which I refer to as cases of sensory perception and imagination, insofar as they are simply modes of thinking, do exist within me – of that I am certain [AT VII, 35].
3 Different Types of Ideas InnateAdventitiousInventionsAmong my ideas, some appear to be innate, some to be adventitious, and others to have been invented by me [AT VII, 37-8].
4 External ThingsAll these considerations are enough to establish that it is not reliable judgement but merely some blind impulse that has made me believe up till now that there exist things distinct from myself which transmit to me ideas or images of themselves through the sense organs or in some other way [AT VII, 39].
5 Identity of IdeasBut it now occurs to me that there is another way of investigating whether some of the things of which I possess ideas exist outside of me. In so far as the ideas are simply modes of thought, there is no recognisable inequality among them: they all appear to come from within me in the same fashion [AT VII, 40].
6 Degrees of RealityObjective RealityFormal RealityEminent Reality
7 Objective Reality Tree The objective reality of the idea of the triangle, for example is the idea of the triangle insofar as it represents the triangle as a thing. The objective reality is not the thing represented, but the representation.Tree
8 Formal RealityThe formal reality of the idea describes the status of the idea itself. Whatever idea we speak of and whatever this idea might represent, the idea itself exists. Again if we go back to our picture example, being mindful that ideas are not pictures for Descartes, so that this is only an analogy, then we can make a distinction between the picture, on the one hand, and what the picture represents on the other. Now the picture, on this analogy, is the formal idea. That is to say idea of the tree itself, and not the tree that is represented in the idea
9 Eminent RealityFor Descartes ideas themselves and not just what they represent in the idea, have degrees of reality. Reality meaning perfection. It is possible to say that some ideas, formally speaking are more perfect than other’s. The idea of frog is less perfect than the idea of God. The idea of God does not just have more formal reality than the idea of frog; rather it has more formal reality than other reality. The idea of God, therefore, for Descartes, has eminent reality.
10 Formal/Objective Reality The degree of reality of formal reality corresponds to the degree of reality of objective reality
11 Formal/Objective Reality In order for a given idea to contain such and such objective reality, it must surely derive it from some cause which contains at least as much formal reality as there is objective reality in the idea [AT VII 41].
12 Formal/EminentIf 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, 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 [AT VII, 42].
13 GodBy the word ‘God’ I understand a substance that is infinite, eternal, immutable, independent, supremely intelligent, supremely powerful and which created both myself and everything else…that exists. All these attributes are such that, the more carefully I concentrate on them, the less possible it seems that they could have originated from me alone. So from what has been said it must be concluded that God necessarily exists [AT VII, 45].
14 ExistenceFrom whom, in that case, would I derive my existence? From myself presumably, or from my parents, of from some other beings less perfect than God; for nothing more perfect than God, or even as perfect can be thought of or imagined. Yet if I derive my existence from myself, then I should neither doubt nor want, nor lack anything at all [AT VII, 48].
15 Principle of Conservation For it is quite clear to anyone who attentively considers the nature of time that the same power and action are needed to preserve anything at each individual moment of its duration as would be required to create that thing anew in it were not yet in existence. Hence the distinction between preservation and creation is only a conceptual one [AT VII, 49]
16 ConclusionI recognise that it would be impossible for me to exist with the kind of nature I have – that is, having within me the idea of God – were it not the case that God really existed [AT VII].