1. We may doubt of all things, unless there appears a new technology of which we are not currently aware.
2. The mind has a unique freedom to doubt whatever it wants to doubt.
3. However, it cannot doubt the fact that it is alive.
4. Why is this general doubt useful?
   • Because it removes prejudice.
   • Because it gives the mind a way to witdraw from the senses.
   • It validates our findings.
     

1. The mind has a unique freedom: it can doubt that any object whatsoever exists, if it has the slightest doubt.
2. However, the mind finds that itself has to exist. This is important, for in this way the mind distinguishes its own awarenes from bodily (sensory) input.
    

Argumentation that the soul is immortal:

1. We are able to form a clear conception (conceptus) of the soul itself.
2. This conception is completely separate from all notions of body.
3. We require an assurance that all objects about which we clearly think, really exist in that same mode in which we "think" them.
4. We need a distinct conception of corporeal nature (i.e. distinct from the soul).
5. We need to conclude that objects that are clearly conceived to be diverse substances, such as mind and body, are really reciprocially distinct substances.
6. NB: We cannot conceive as the body except as divisible; and we cannot conceive of the mind except as indivisible. 
7. All things that can only exist because they were created by God, are in their own nature incorruptible. (e.g. the human soul).
8. The human body is made up of a certain configuration of organs and through other "accidents". The mind is not made up of accidents, but is a pure substance.
9. The mind can also have "accidents" - it can think certain things, will others and perceive yet others; however the mind itself does not vary with these changes.
10. However, the body is no longer the same if any part changes.
11. THUS the body may perish easily, but the mind is in its own nature immortal.

1. In Three he unfolds his chief argument for the existence of God. (But remember, he avoids comparisons taken from the material worlds, so that he might withdraw the minds of his readers from the senses).
2. He foresees an objection to the following: How can there be the objective reality of a being who is absolutely perfect in our minds?
3. This being participates by representation in so many degrees of being and perfection that it must be regarded as arising from a source that is absolutely perfect.
4. In the same way that the building of a perfect machine requires perfect plans, so the idea of God, which is found in us, must be drawn from God Himself.

1. All which we clearly and distincly perceive (apprehend) is true.
2. How errors arise.
3. He does not treat of sin, but only of error with regard to true or false.
4. Also, he does not refer to matters faith or ethics, but only with regard to speculative truths, and only as is revealed by the natural light.

1. He gives a new demonstration of the existence of God.
2. The certitude of geometrical demonstrations itself is dependent on the existence of God.

1. The act of understanding (intellectio) is distinct from that of the imagination (imaginatio). The characteristics of this distinction are described.
2. While the mind is distinct from the human body, it is also so closely conjoined with the body as to form a unity.
3. He reviews all the errors that arouse from sensory input.
4. He points out ways to avoid the perceptory errors.
5. He adduces all the ground from which the existence of material objects may be inferred.
6. Everybody knows that the world and meterial objects exist, but he is pointing out that the proofs for the material world are not as clear and strong as those that conduct us to the knowledge of our mind and of God. Therefore the mind and God are of all human knowledge the most manifest.
7. The fact that the mind and God are more present to the mind itself than are material objects - that is the single aim of his meditations.