The title of the first Meditation is “what can be called into doubt”. Here Descartes lays out his method of doubt, calling on the reader to give up those beliefs which cannot be rendered absolutely certain. Descartes (or the Meditator) motivates the method by claiming it as necessary if one wanted “to establish anything in the sciences that was stable and likely to last” (AT VII:17)
A Foundationalist Project
A common way of understanding the structure of human knowledge, and one which Descartes seems to endorse, considers some bits of human knowledge as more basic than others, and considers the warrant for this more derivative knowledge as deriving from the more basic. The basic knowledge is not dependent on its being inferred from any other knowledge. This is what makes it basic. Call the position that all knowledge (or warrant) rests ultimately on a foundation of non-inferentially acquired knowledge (or warrant) foundationalism.
The Meditator seems to endorse a foundationalist conception of human knowledge in the opening paragraphs of the First Meditation, and of pursuing a strategy of establishing a stable and lasting science on foundations which are immune to doubt. The Meditator also makes clear that he is interested primarily in theoretical knowledge rather than knowledge sufficient for guiding action.
For indeed I know that meanwhile there is no danger or error in following this procedure, and that it is impossible for me to indulge in too much distrust, since I am now concentrating only on knowledge, not on action. (AT VII:22)
If it is clear that Descartes (or the Meditator) pursues a foundationalist epistemology in the Meditations, it is less clear how we should construe the nature of this foundation. Descartes is looking for those beliefs or judgments for which doubt is impossible. We can distinguish two different ways in which this might be meant, and thereby two different projects to pursue, and it is not always clear which one Descartes prefers. On the one hand, we have a normative project of working out which beliefs we are epistemically entitled to hold. These are the beliefs, given the Meditator’s method of doubt, concerning which there is no reason to doubt. On the other hand, there is the wish to create a stable and lasting foundation for the sciences. In other words, a foundation that we are psychologically unable to doubt (cf. (Smyth 1986); (Loeb 1990); (Bennett 2001)).
It may well be that these two projects are compatible. But it isn’t obvious that they converge. One may be unable to doubt what is nevertheless false, and one may be rather uncertain of what is in fact true.
The Method of Doubt
In order that he may arrive at a correct metaphysics Descartes argues that we must suspend judgment concerning any proposition whose truth is not known with absolute certainty.
[To accomplish the goal of determining which of my judgments are absolutely certain] Reason now leads me to think that I should hold back my assent from opinions which are not completely certain and indubitable just as carefully as I do from those which are patently false. So, for the purpose of rejecting all my opinions, it will be enough if I find in each of them at least some reason for doubt. (AT VII:18)
One might reasonably ask why this is necessary. Couldn’t we just hive off our metaphysical beliefs from our other beliefs until we figure out the correct metaphysical theory? Descartes suggests otherwise. He compares his method to one in which one sorts the bad apples out of an apple basket.
Suppose he had a basket full of apples and, being worried that some of the apples were rotten, wanted to take out the rotten ones to prevent the rot spreading. How would he proceed? Would he not begin by tipping the whole lot out of the basket? And would not the next step be to cast his eye over each apple in tum, and pick up and pour back in the basket only those he saw to be sound, leaving the others? In just the same way, those who have never philosophized correctly have various opinions in their minds which they have begun to store up since childhood, and which they therefore have reason to believe may in many cases be false. They then attempt to separate the false beliefs from the others, so as to prevent their contaminating the rest and making the whole lot uncertain. Now the best way they can accomplish this is to reject all their beliefs together in one go, as if they were all uncertain and false. They can then go over each belief in turn and re-adopt only those which they recognize to be true and indubitable. (VII:481)
Since the false beliefs ‘contaminate’ and potentially render ‘the whole lot uncertain’ Descartes argues the best strategy is to turn them all out in one go. Otherwise, he seems to think we run the risk of retaining false beliefs, which may be hidden among the good ones that they have ‘contaminated’.
The Goal of Doubt
In the synopsis Descartes says concerning his method of doubt that,
its greatest benefit lies in freeing us from all our preconceived opinions, and providing the easiest route by which the mind may be led away from the senses. The eventual result of this doubt is to make it impossible for us to have any further doubts about what we subsequently discover to be true. (VII:12)
So the method of doubt is supposed to have a positive and salutary effect on the belief system of the doubter, bringing them around to what Descartes believes are the correct metaphysical beliefs, which cannot themselves be doubted.
This is important to notice, because it shows that Descartes is not interested in skepticism for its own sake, nor simply for its role in freeing the mind from prejudicial beliefs, but rather specifically for its capacity to orient the subject towards the correct metaphysical view.
One further question is whether the method of doubt is supposed to yield anything further than a proper basis for physics. In particular, several interpreters have argued that Descartes’s broader aim is a vindication of reason, either in the weak sense of investigating all grounds for doubt and finding them flawed, or in the strong sense of demonstrating that not only are there no grounds to doubt the capacity of reason to grasp truths about reality, but there is in fact a positive basis for believing that reason alone could provide knowledge of the nature or structure of reality (see (Hatfield 2003), 94-5; cf. (Frankfurt 2008), ch.1; (Williams 1978), ch.2). The progression of Descartes’s argument in the Meditations plausibly provides some basis for the weak vindication. Because of the demanding nature of its claim, the strong vindication stands in greater doubt. We’ll return to this in our examination of the other meditations.
The lion’s share of the First Meditation is concerned with doubting the deliverances of sense. The structure of the argument proceeds roughly as follows:
- Sensory foundations (VII:18)
- Sensory fallibility (VII:18-19)
- Objection: Optimal circumstances (VII:19)
- Objection: Insanity (VII:18-19)
- The dream argument (VII:19)
- Objection: The painter’s analogy (VII:19-20)
- Deceitful God; Dubitability of mathematics (VII:21)
- The corrective role of doubt (VII:22)
- The evil demon (VII:22-3)
Why argue against empiricism? There are at least two reasons motivating Descartes. The first is that empiricism is dominant in Aristotelian school philosophy. Insofar as Descartes is looking to articulate a new foundation for physics, one distinct from that traditionally offered by Scholastic Aristotelianism, he needs to argue against their epistemology.
Second, Descartes also considers empiricism to capture the natural human default attitude. He begins ¶3 of the First Meditation with the claim that “Whatever I have up till now accepted as most true I have acquired either from the senses or through the senses.” He says this not just because it is a scholastic doctrine but because he thinks it the natural human attitude to trust the senses above all, and if nothing else, then out of habit (¶11, ATVII:22). One way to thus understand the aim of the Mediations is as attempting to dislodge the meditating subject’s trust in the senses and the epistemic habits formed therefrom.