Sometimes, in philosophy, a thinker decides to start anew from the principle, in attempting to give a novel, solid foundation to their thought as well as to philosophy itself. Needless to remind ourselves here, how the necessity for an incontestable – elenctic – foundation is a task of primary importance for a philosopher who desires to elevate their thoughts to a system. A similar attempt, if successful, becomes a real revolution within the history of thought, and leaves a deep and everlasting legacy. René Descartes is undoubtedly a member of this circle of thinkers.
What follows is the first step towards an end to rational theology – albeit, as we shall see, this was probably not Descartes’ original intention. It does not alter the fact that his attempt to establish in a certain and indisputable manner the gnoseological, and therefore ontological, foundation in order to pave the way for later thinkers to detach philosophy from theology. However, in various forms, the concept of God still remains as the foundation or summit of philosophical systems.
[…] as long as I think, then I know that I am at least something that thinks: I think therefore I am – I am, I exist [cogito ergo sum – ego sum, ego existo].
Meditations On First Philosophy (Meditationes de prima philosophia), which was published in 1641, is the work that will be referred to. The subheading clearly reveals the author’s intentions: “in which the existence of God and the distinction of the soul from the body are demonstrated”. In order to fulfil these intentions, Descartes considered it necessary to start from an indisputable gnoseological foundation in order to free himself from any errors present in previous philosophical thought. And, at the same time, to be certain that any conclusion reached was in Truth and without any doubt or, in his own words, clear and distinct. The first part will therefore, be devoted to the pars destruens of the discourse, and indeed it can be said that Descartes makes – or at least intends to make – a tabula rasa of all that has been thought previously. We will now read the incipit of the first meditation:
By ‘omnia’ Descartes really meanteverything, and not only philosophical principles – even though this is only to be understood on a theoretical level, since he makes it clear in the Principia philosophiae that it would be foolish to apply such method to our daily life. However, the laws of the world, the very existence of the world, of physical things, of unfathomablebeings, even of one’s own existence – in short, everything that has ever been perceived or thought – must be questioned. This position is usually referred to as ‘hyperbolic doubt’ and is explained in a significant passage of his first meditation:
The motto is ‘doubt everything’ because you can never be sure that anything is true in the deepest and most unquestionable sense of the term. At this point, however, one finds oneself in a thorny situation: certainly, one does not run the risk of taking for certain something that is false, but at the same time one cannot consider anything as true. Thus, without solid foundations, thought itself is annihilated, because it can no longer take a step without running the risk of falling into the abyss of nonsense, erroneous, or falsehood. What is required is an anchorage, an Archimedean fulcrum on which to pryandassemble according to truth what has been denied. And it is precisely here that the elenctic movement makes its appearance, which, as we have already seen, is the only true foundation of undeniable Truth. Let us follow our author once again in the second meditation:
Nothing else but this: maximum rational power manifested in maximum simplicity. If I think I am constantly being deceived, I cannot doubt the fact that I think I am being deceived; if I doubt, I cannot doubt the fact that I am doubting; as long as I think, then I know that I am at least something that thinks: I think therefore I am – I am, I exist [cogito ergo sum – ego sum, ego existo]. The elenctic movement, in this structure of thought, is expressed as follows: in order to doubt my existence, I must suppose that I exist as something that doubts. If I also deny that I exist, I must assume that I exist as something that denies its own existence. The proposition ‘I deny that I am’ presupposes the truth of the proposition ‘I am’, ergo the proposition ‘I exist’ has elenctic status, because it is reaffirmed even by its own denial.
At this point, however, Descartes has only demonstrated that as long as one thinks, one is something, and precisely that one is ‘something that thinks’ [res cogitans]. It is another thing to show that one’s own body really exists and that the perceptions that are imprinted in it and then processed by thought come from an external world consisting of entities that in turn exist. The point is: how can I truly demonstrate that there is something further than the ‘thinking thing’ that I am? Divine intervention is necessary, it must be said, and God himself must guarantee the truth of the world’s existence. The next step, therefore, is to demonstrate the existence of God.
A ‘thinking thing’, by definition, ‘thinks’, and this is tautological. If it thinks, then it also possesses ideas, which are the contents of its thinking and in particular are ‘images of things’ (which are distinguished from other thoughts such as will, affections and judgements). Among these there are some that are fogged and confused, and others that are clear and distinct; for Descartes, the former are certainly false, while the latter are true: “it seems to me that I can already establish as a general rule that all things which I perceive very clearly and very distinctly are true”.Of all the clear and distinct ideas, the clearest and most distinct of all is the idea of God and his perfection and infiniteness. Descartes excludes, by means of certain demonstrations, that this idea can come from the perception of finite entities external to the ‘I think’ (because one never perceives a perfect or infinite entity), and at the same time excludes that this idea is created by the ‘I think’ by subtraction or addition of qualities to finite entities (as darkness is the absence of light, or numerical infinity is the sum of all numbers). Only one prospect remains: the idea of God comes to the ‘Ithink’ directly from God, and therefore the cause of something real. This idea must have at least as much reality as its effect. Therefore, the cause of the idea of perfection must be something perfect, and the cause of the idea of infinity must be something infinite. This brief summary does not do justice to all of Descartes’ arguments, it would indeed be too long to summarise them in full here. However, it does lead to a general understanding of why the philosopher might write, in his third meditation: “we must of necessity conclude from the fact alone that I exist, or that the idea of a Being supremely perfect ‒ that is of God ‒ is in me, that the proof of God’s existence is grounded on the highest evidence”.
The last passage, which closes the Descartesian gnoseological foundation, recognises that God, since perfect, cannot be an evil deceiver. This is because wickedness and deception are deprivations of perfection that cannot belong to the most perfect being in any manner. The concepts of perfection and wickedness or deception are incompatible if not contradictory, and therefore God cannot wish to deceive man. At this point all that is left is to specify that fallacy and falsehood are consequences of the unbalanced relationship of two human faculties: the intellect and will. The intellect is finite, imperfect, and proceeds only within its own limits; will, on the other hand, is a manifestation of the free will that God has given to man, it is perfect, and wants far more than the intellect can actually manage. Whenever will is empowered to exceed the capabilities of the intellect, one falls into error, one assumes falsehood to be true.
Therefore, reality outside the ‘I think’ exists, the world exists, and God is the guarantor of its existence. He is also the guarantor of the truth of everything we perceive clearly and distinctly. Yet, every error, every confused or distorted idea, and every false belief is attributable to the inability of managing one’s own will.
Descartes’ elenctic foundation of ‘I think’ and the gnoseology that stems from it are a cornerstone in the history of philosophical thought. It would be difficult to envisage the work of great modern and contemporary thinkers if Descartes had not previously opened up this path.
 All quotations from this work are from the volume: René Descartes, Meditations On First Philosophy, in The Philosophical Works of Descartes, translated by Elizabeth S. Haldane, Cambridge Univesity Press 1911.
 Ivi, Meditations I.
 Ivi, Meditations II.
 Ivi, Meditations III.