# XIV explained — Philosophical Works

> Chapter companion for Philosophical Works by René Descartes.

## What happens

The mind reviews its ideas and discovers the idea of an absolutely perfect Being, in which necessary and eternal existence is contained, just as the equality of angles is contained in the idea of a triangle; from this it validly infers that the all-perfect Being exists.

## Themes in this chapter

### Existence of God

The chapter argues that necessary existence is contained in the idea of an all-perfect Being, thus proving God's existence.

### Reason and Method

The inference from the idea of perfection to God's existence follows the same logical method as geometric proofs.

## Character check-ins

### Narrator

The mind that reviews its ideas and infers God's existence.

### God

The all-perfect Being whose necessary existence is inferred from the idea of perfection.

## Key lines

> When the mind afterwards reviews the different ideas that are in it, it discovers what is by far the chief among them⁠—that of a Being omniscient, all-powerful, and absolutely perfect; and it observes that in this idea there is contained not only possible and contingent existence, as in the ideas of all other things which it clearly perceives, but existence absolutely necessary and eternal.

When the mind examines its own ideas, it finds the most important one: the idea of a perfect, all-knowing, all-powerful Being. Unlike other ideas, which only imply possible or temporary existence, this idea includes necessary and eternal existence.

_This passage sets up the ontological argument by distinguishing the idea of God from all other ideas._

> And just as because, for example, the equality of its three angles to two right angles is necessarily comprised in the idea of a triangle, the mind is firmly persuaded that the three angles of a triangle are equal to two right angles; so, from its perceiving necessary and eternal existence to be comprised in the idea which it has of an all-perfect Being, it ought manifestly to conclude that this all-perfect Being exists.

Just as the mind is convinced that a triangle's angles sum to 180 degrees because that property is part of the idea of a triangle, so too should it conclude that the all-perfect Being exists, because necessary existence is part of the idea of that Being.

_Descartes uses a geometric analogy to argue that existence is as inseparable from the concept of a perfect being as angle sum is from a triangle._

## Links

- HTML: https://www.betterreads.online/discover/philosophical_works_se/chapters/xiv
- Book: https://www.betterreads.online/discover/philosophical_works_se
- All chapters: https://www.betterreads.online/discover/philosophical_works_se/chapters