# IX explained — Philosophical Works

> Chapter companion for Philosophical Works by René Descartes.

## What happens

Descartes defines thought (cogitatio) as all that we are immediately conscious of, including understanding, willing, imagining, and even perceiving. He argues that while bodily acts like seeing or walking can be doubted, the consciousness or sensation of those acts is certain because it belongs to the mind alone.

## Themes in this chapter

### Cogito Ergo Sum (I Think, Therefore I Am)

Descartes clarifies that the certainty of 'I think, therefore I am' extends to all modes of thought, including the consciousness of seeing or walking.

### Mind-Body Dualism

Descartes distinguishes between bodily acts (which can be doubted) and the mind's consciousness of those acts (which is certain), reinforcing the separation of mind and body.

## Character check-ins

### Narrator

The narrator (Descartes) defines thought and distinguishes bodily acts from the consciousness of those acts.

## Key lines

> By the word thought, I understand all that which so takes place in us that we of ourselves are immediately conscious of it; and, accordingly, not only to understand ( intelligere , entendre ), to will ( velle ), to imagine ( imaginari ), but even to perceive ( sentire , sentir ), are here the same as to think ( cogitare , penser ).

Descartes defines thought as anything we are directly aware of in ourselves, so that understanding, willing, imagining, and even sensing are all considered forms of thinking.

_This broad definition of thought is central to Descartes' epistemology, as it grounds certainty in immediate consciousness._

> For if I say, I see, or, I walk, therefore I am; and if I understand by vision or walking the act of my eyes or of my limbs, which is the work of the body, the conclusion is not absolutely certain, because, as is often the case in dreams, I may think that I see or walk, although I do not open my eyes or move from my place, and even, perhaps, although I have no body: but, if I mean the sensation itself, or consciousness of seeing or walking, the knowledge is manifestly certain, because it is then referred to the mind, which alone perceives or is conscious that it sees or walks.

If 'I see' refers to the physical act of seeing, it can be doubted (as in dreams), but if it refers to the conscious experience of seeing, it is certain because that consciousness belongs to the mind alone.

_This distinction reinforces the mind-body dualism and the certainty of the cogito._

## Links

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