Skepticism: philosophical perspectives and critical thinking

Descartes and Skepticism

Skepticism is the definition where each and every aspect of one's knowledge -- including belief of one's reality is questioned. Determined to investigate the source and truth of his knowledge, Descartes determined to start by doubting all that he knew and then to work through each and every element of his presupposition -- both cultural and sensual and even the fundamental basics of reasoning itself -- in order to arrive at some sort of infrastructure of knowledge that he could accept as certain. This became known as the Cartesian framework or endeavor towards certain knowledge.

His book the Meditaitons describes this search. His First Meditation is the elaboration of his exercise on three levels. Firstly, Descartes notes that all of existence may be an illusion. Just as dreams are illusions, so too may existence be one long drawn out delusion too. It is, therefore, recommended to doubt any particular bit of sensory knowledge except that of mathematics and the content of simple nature since these remain constant even in an abstract existence.

Furthermore, Descartes brings up the possibility of a deceiving God, namely one who belabors to induce humans to believe in an existence that is untrue. Perhaps I systematically deceive myself, or there is some demon (if not God) that distorts my reality. The point is uncertainty in the certitude of any of my beliefs.

Descartes then proceeds to show that the one element that emerges as assured is the fact "cogito ergo sum," "I exist, therefore I am" (Med. II). I think, therefore I am. I have this thought of skepticism therefore I must exist, and no demon could deceive me regarding that. "Cogito ergo sum" acts as an intuition of one's own reality, an expression of self-conscious awareness.

From this basis, flows all else. What is this sum? Asserts Descartes, it is a mind or soul: sum res cogitans" ("I am a thing that thinks") (Med. II). All external impression are printed on the mind as imprint on beeswax. Whilst sensory appearances may be unreliable, it is the mind -- introspection -- that provides the key to authentic knowledge. Nonetheless, we may still be deceived by some sort of demon -- perhaps our innate ideas do not correspond to the reality of things (Med III).

Descartes then proves that God does exist by arguing that the cause of my idea must have at least as much reality as the content of the idea itself. Since my concept of God has unlimited content, the initiator of this idea must be infinite and this description can only apply to an omnipotent infinite creator. Therefore God exists, and Descartes' reinforces this supposition with the classical cosmological argument. A perfect God would not wish to deceive (Med. IV), and, therefore, I can now be certain that my innate ideas (or intellectual / cognitive capacities) cohere to an external reality. Errors come about through the organ of the will rather than through the organ of the understanding, since I misuse my free will to assent on occasions when my understanding is incomplete (Med. IV). Mathematics -- clear and indubitable - can help us find the truth (Med. V).

In the following Meditations, Descartes attempts to prove that there is a material world and that bodies do really exist before discussing the mind-body (dualism) distinction.

Al-Ghazali and Skepticism

Abu Hamid Muhammad al-Ghazali's book al-Munqidh min ad-Dalal (1058 AD) or 'The Deliverance from Error' delineates al-Ghazali's refutation on the validity and reliability of all knowledge. For knowledge to be certain -- and to be considered as such -- it must be free of all doubts and illusions. A thorough assessment of the fields of knowledge existent at this time ("There is no philosopher whose system I have not fathomed, nor theologian the intricacies of whose doctrine I have not followed out") told him that certainty of all was to be denied, since knowledge is based either as reliance on sense perception or as reliance on intellectual acquisition. Al-Ghazali, through his investigations, showed that both certainty of sense-perceptions (e.g. though the shadow of a stick that seems to imply that the stick is moving when it is not) and certainty of alleged intellectual truths (i.e. The possibility of judging an alleged fact in opposing and diverse manners) could be questioned.

Turning to dreams, al-Ghazaali illustrates that wakefulness is simply a higher consciousness of the dream state. Might there not be, therefore, (he questions), a state beyond that of habitual living that denotes a higher consciousness to that of life itself, hence, nullifying whatever beliefs we might cherish in this mundane world of ours? A hadith supports his supposition: "The people are dreaming, (but) when they die, they become awake." The Sufis call this a special mystic state of ecstasy when we have withdrawn into ourselves and are distinct from our senses.

Similarities and Differences between Al-Ghazali and Descartes

Similarities are striking in that both Descartes and al-Ghazali questioned the veracity of intellectual and sensory knowledge. Both set about examining their cognitive structures, although in reverse directions. Descartes commenced with presuming that all knowledge were questionable and he set about erecting a secure foundation on which he could base his beliefs, whilst al-Ghazali commenced by asserting belief then investigating how he could 'cut the ground out' from under that belief (and he did so by demonstrating that both empirical and intellectual knowledge could be spurious).

A striking similarity in both philosophical structures was the concept of an external Judge or force. To Descartes, that was a deceptive God or a demon that could have distorted our reality. To al-Ghazali that was a Judge who may have had an alternative perspective on much of our intellectual certitudes.

Both Descartes and al-Ghazlai obsessed on the similarity between the apparent reality of the dream state and the realm of wakefulness. To Descartes, however, that led to thoughts of whether reality itself could be trusted (was it not as dream?), whereas al-Ghazlai went on to promote a higher state of consciousness external to this mundane reality that could disprove all of our certainties; just as wakefulness is a state superior to dreams, so too could a higher more mystic level exist beyond this state called 'life'.