|Précis of the Fourth Meditation (Truth and Falsehood)
1. After practising his meditating, Descartes now finds it easier to concentrate on that which is ‘purely intelligible’ to the mind, in other words to just reason about things. It is clear that he exists while he is thinking; that God exists; that Descartes’ existence relies on God. Knowledge of God can lead to greater knowledge – the ‘treasures of the sciences and of wisdom’.
2. He notes that since fraud and deception involves imperfection, God (who is wholly perfect) is not a deceiver.
3. Descartes experiences the faculty of judgement in himself. This faculty is a gift from God and, as such, can be relied upon to deliver the truth (God would not wish him to be mistaken since this is deceitful).
4. That said, how can he explain the obvious fact that he has made mistakes? What is the source of these errors? He reflects that he is part-way along a spectrum running from God (all perfections) to nothingness (complete absence of perfections). He is a mixture of part-God, part nothingness and it is unsurprising if the latter gives rise to error, imperfect as it is. Certainly, Descartes’ errors are no fault of God’s – they could merely result from the fact that Descartes’ faculty for judging correctly is not infinite.
5. But this is not a full explanation since error is not simply an opposite of perfection. Rather, it is a lack of some knowledge ‘it seems I ought to possess’. Surely a perfect God would have created Descartes’ mind such that it always worked perfectly; that God would want Descartes to find truth? Is it a possibility that it is somehow better that Descartes makes mistakes?
6. When this thought strikes him, Descartes acknowledges that he should not be surprised if God’s ways remain mysterious to him - God’s mind being such a superior article compared to Descartes’. This alone persuades him to abandon any examination of God’s purpose (‘the whole class of final causes’) for the world.
7. Considering that God’s aim is for the best, then Descartes cannot just consider himself: this best might emerge from the interaction of all the parts of the world considered together rather than individually. Even though Descartes hasn’t yet proved to himself that anything exists apart from himself and God, nonetheless, God might have created other things about which Descartes will never know.
8. On deeper reflection, Descartes notes that the source of the errors he has within him depend on two things which always happen together when making a judgement: his faculty of knowing (understanding or intellect); his free will. Knowing alone cannot lead him into error since this is merely the conceiving of the ideas of things. It is the affirming or denying of what presents itself to his judgement that counts (his free will, in other words). His faculty for knowing (or power of reasoning) is perfect in that it will deliver the truth (eg the Cogito, the knowledge that God exists).
9. God has also given him a will (or freedom of choice) which is unlimited. In this respect, he has a capacity which is like God’s and persuades him that his nature and God’s nature are aligned. This although God is greater, with more power: nonetheless it appears to Descartes that he also has infinite free will. This free will consists merely in choice of one course rather than another. It isn’t necessary that there always be a choice for the will – when moved towards certainty (as in the Cogito) there is no choice for the will: Descartes (like any reasoning mind) is forced to accept the truth. This in not a fault in the will. Rather, it is a fault in our knowledge if we do experience the freedom to choose – if we truly knew then we would (as in the Cogito) not have to exercise the will at all.
10. The power of the will is a perfect gift from God, and so is the power of understanding. The errors he makes arise from his will ranging over things he does not understand. And given that the understanding is needed if the will is to choose wisely, it is unsurprising that the will sometimes gets it wrong and chooses the wrong course: Descartes errs or sins.
11. He gives as an example of this what he has recently discovered: his understanding told him that he was a thinking thing, and shortly afterwards his will to believe this was very great indeed. Conversely, he was also presented with the idea that there is a material world which exists too which may, or may not, of the same stuff that he consists in. His understanding has yet to persuade him either way [monist or dualist] and so his will to believe could still go either way.
12. This doubt (‘indifference’ or still being open to choosing) about what to believe extends to all things of which the understanding has no knowledge – including things about which we can only conjecture.
13. So, he resolves to judge nothing which he does not understand ‘clearly and distinctly’ so that he will be immune from error. Lack of knowledge comes from the way Descartes uses the gift of understanding which God has given him rather than the gift itself.
14. He is thankful for the few gifts he has received from God - even if the gift of the will he has been given is infinite and thus allows the possibility of Descartes making mistakes. The mistakes made cannot be traced back to God since they are due to the agent’s neglect rather than God’s Will. The imperfections of erring fall squarely on Descartes not employing his understanding as wisely as he might, but by being rash in his thinking.
15. He cannot complain that God did not give him understanding and free will that were co-extensive (so ruling out error altogether): Descartes would not want less free will than he has
16. Nor should he complain that God is complicit in Descartes’ errors. His errors stem from a lack (a privation). And since God lacks nothing, they cannot logically stem from Him. The errors come from Descartes judging outside the sphere of his knowledge. Yes, God could have made Descartes incapable of error but it is undeniable that it remains a possibility that the universe may be better for having in it parts (such as Descartes) which are not immune from error.
17. He can avoid error not just by only judging within his sphere of knowledge. He can also save himself from error (or, at least, from as many errors) by abstaining from making a judgement when his knowledge is not extensive enough.
18. Finally, this meditation has made clear that the source of his errors is Descartes alone but that knowledge of the truth is possible – and that ‘clear and distinct perception’ lets him know when this is arrived at. He resolves to be diligent in restricting judgements to within his sphere of knowledge in future.