I Think Therefore I Am

My first meditations are so metaphysical and so uncommon. They might not be acceptable to everyone.

The foundations that I have laid are secure.

Our opinions are highly uncertain. We should reject as absolutely false all opinions which could be doubted. This is so that we can have solid truths.

Our senses sometimes deceive us. That is why I supposed that there existed nothing really such as they presented to us.

This is because some men:

• err in reasoning, and
• fall into paralogisms, even on the simplest matters of geometry

I was as open to error as any other. So I rejected as false all the reasonings I had hitherto taken as fact.

The very same thoughts which we experience when awake may also be experienced when we are asleep.

But when asleep, they are not true.

But it means that all the objects (presentations) that I had in my mind when awake were just as false as the illusions of my dreams.

I thus wished to think that all was false even myself who was thinking of it.

The Non-Physical Existence

I realized that I think, therefore I exist (cogito ergo sum). This was so certain that it could not be doubted.

This is the first principle of my philosophy.

If I had no body, then I would not have any physical existence. But it does not mean that I could not have a [non-physical] existence.

On the contrary, it most clearly and certainly followed that I could exist [as I could think about it].

On the other hand, if I stopped thinking then I would no longer exist, even if all the other objects which I had imagined retained their existence in reality.

I thence concluded that:

• I was a substance whose whole essence or nature consists only in thinking
• this substance may exist without physical place, or any material thing
• this “I” is the mind by which I am what I am
  • It is wholly distinct from the body
  • It is even more easily known than the body
  • It would exist even if the body did not.

“I think, therefore I am” has nothing which assures of their truth beyond this.

As a general rule, all the things which we very clearly conceive are true.

However, there is some difficulty in rightly determining the objects which we clearly conceive.

My being was not wholly perfect. So I thought of something more perfect than myself.

I came up with the idea of God as perfection.

I knew some perfections which I lacked. It meant that:

• I was not the only being in existence.
• there was logically some other more perfect Being whom I was dependent on, and from whom I had received all that I possessed.

If I had existed alone, and independently of every other being so as be perfect, then I would never be able to think of the words “infinite”, “eternal”, “immutable”, “omniscient”, “all-powerful” and all the other things that I was not.

I therefore put all these perfections in God.

For in order to know the nature of God, I only had judge whether all the properties in my mind are perfect.

Thus, I perceived that doubt, inconstancy, sadness, etc, could not be found in God, since I myself would have been happy to be free from them.

Besides, I had ideas of many sensible and corporeal things.

I might have been dreaming when I had them.

They might be false. But they are still my thoughts.

But I had already very clearly recognized in myself that the intelligent nature is distinct from the corporeal.

Conservation Laws by God

All composition is an evidence of dependency. Thus, a state of dependency is manifestly a state of imperfection.

I therefore determined that it could not be a perfection in God to be compounded of these 2 natures.

• Consequently, he was not so compounded.

Any bodies, intelligences, or other natures that were not totally perfect would have their existence depend on his power.

They could not subsist without him for a single moment.

I represented to myself the shapes of the geometers. I conceived them to be a continuous body or a space:

• indefinitely extended in length, width, and height or depth
• divisible into parts which admit of different figures and sizes
• capable of being moved or transposed in all manner of ways.

These demonstrations lead to common consent, producing great certitude.

This consent is based on the fact that they are clearly conceived in accordance with the rules I have already laid down.

In the next place, I perceived that there was nothing at all in these demonstrations which could assure me of the existence of their object.

Thus, I distinctly think of a triangle has its 3 angles being equal to 2 right angles.

• But it does not mean that any triangle existed in reality.

On the contrary, if my basis is the existence of the idea of 3 angles to 2 right angles, then it follows that the idea of a triangle exists.

If points that are equidistant from the center exists, then it follows that a sphere exists.

I found existing things in my thoughts. If follows that a Perfect Being that has all these thoughts exists.

Consequently, God, this Perfect Being, exists just as the shapes of geometry exist.

People have trouble realizing this because they never raise their thoughts above sensible objects.

They are so used to consider only the ideas from material objects, that all that is not materially imaginable seems to them not intelligible.

Philosophers of the schools accept as a maxim that:

• all our understanding comes from the senses
• the ideas of God and of the soul have never been through our senses

Thus, those who perceive God and the soul through the material senses are like people who use their eyes to hear sounds or smell odours.

People who still doubt the existence of God and the soul should learn all my other propositions.

God and the soul exist just as we have a body and just as the stars and the earth exist.

We have a strong moral assurance of these things.

When we are asleep we might dream of:

• ourselves being in another body
• seeing other stars and another earth

This is even if those things to do not seem to exist.

How do we know that the thoughts in our dreams are false compared to our thoughts when awake?

Genius men study this question as long as they want.

But they will be able to give any reason which can remove this doubt, unless they presuppose God’s existence.

For, in the first place even the principle which I have already taken as a rule, viz., that

My rule was that all the things which we clearly and distinctly conceive are true.

This rule is certain only because God:

• exists
• is a Perfect Being
• is the source of all that we possess

It follows that our ideas or notions, which to the extent of their clearness and distinctness are real, and proceed from God, must to that extent be true.

We frequently have ideas or notions which have some falsity.

• Such ideas are therefore confused and obscure
• This obscurity comes from us not being totally perfect

The knowledge of God and of the soul makes us certain of this rule.

The illusions of our dreams does not affect the truth of our thoughts when we are awake.

A sleeping person might get a very distinct idea.

For example, a geometer might discover a new demonstration. His being asleep would not prevent its truth.

The error in our dreams make us question the truth in what we experience when awake, because we are also deceived in the same manner when awake.

For example:

• persons with jaundice see all objects yellow
• we see the distant stars as very small

Whether awake or asleep, we should never be persuaded of the truth of anything unless on the evidence of our reason, and not of our imagination or of our senses.*

For example, we very clearly see the sun. But we should not conclude that it is as small as our eye sees it.

We can distinctly imagine the head of a lion joined to the body of a goat.

But it is not relevant to our reason whether the lion-goat really exists or not.

Our reason simply tells us that all our ideas or notions have some truth in them.

Otherwise, God would not have placed them in us.

Our reasonings are clearer and most complete when we are awake, not when asleep.

Sometimes, our imagination is more lively and distinct than our waking moments.

Our imperfection means that not all our thoughts can be true.

Those possessing truth are found in the experience of our waking moments rather than in that of our dreams.