Descartes’ rejection of scholastic philosophy is the first step in his systematic questioning and radical re-examining of the foundations of knowledge. The medieval interpretation of the physical world entailed an absolute and unquestionable belief in ‘substantive forms’ or inherent essences, manifesting themselves in phenomena such as fire, regarded as ‘consubstantial’, that is, being intrinsically associated, with the presence of fire.

In his ‘Meditations’, Descartes sets out to question the origins of our beliefs in order to make us reevaluate them in the light of first-hand experience. Instead of relying on unexamined (pre)suppositions, the French philosopher wants us to question the very propositions which are meant to support and legitimise these beliefs. Using the image of a basketful of apples, Descartes invites us to discard the rotting and rotten ones in order to spare the good ones from decomposition and decay. The same phenomenon applies to knowledge being contaminated by some tainted, impure elements. We must, therefore, be prepared to eradicate any unreliable proposition, likely to threaten the validity of our whole knowledge. Descartes is not so much fascinated by knowledge itself as by the very possibility of certain and absolute truth. His approach suggests that both notions are inextricably linked in his mind even though, as Bernard Williams comments, ‘the search for the Archimedean point (or perfect, impartial vintage point) is based on an illusion.’

“Using the image of a basketful of apples, Descartes invites us to discard the rotting and rotten ones in order to spare the good ones from decomposition and decay.”

The wax experiment is made possible as well as it acquires its full philosophical legitimacy, only once the very essence of Descartes himself as ‘a thinking thing’ has been pre-established and furthermore, accepted by the reader. However, when the essence of the wax is finally reduced to its being an ‘extended, flexible, changeable’ thing, Descartes’ contention is that such a conclusion is arrived at through nothing but an ‘inspection of the mind’, irrespective of the various ‘sensible’ qualities registered throughout the uninterrupted experiment. It is, therefore, to be assumed, as Descartes invites us to do, that all these observable qualities are derived from a judgement of perception, leading to a simultaneous rational conclusion about the very nature or essence of the piece of wax.

When Descartes writes: ‘I perceive it with my understanding’, he means that his mind monitors and collates the information gathered by his senses in order to reach a mental comprehension of its very essence. Beyond possible misinterpretations of the object under examination, through his own possible defective eyesight, sense of touch, smell or hearing, Descartes, in the final analysis, trusts implicitly in his ‘clear and distinct idea’. Williams draws, here, an illuminating distinction between the observer ‘seeing the wax’, in a direct, sensible way and on the other hand, his alter ego, the philosopher, ‘seeing THAT’, in other words, ‘judging’ that the wax has changed in terms of quality, while preserving its very essence all along.

What is implied, here, is the judgmental or intellectual dimension of all human perceptions. By assuming the possibility of a ‘clear and distinct’ knowledge of wax, beyond its physical existence as physical matter, Descartes is paradoxically putting forward a metaphysical claim, beyond the purely epistemological credentials, set at the very onset of the famous experiment.