---
book: 1
part: "common notions"
source: "https://scaife.perseus.org/reader/urn:cts:greekLit:tlg1799.tlg001.perseus-eng2:1"
license: "CC-BY-SA-4.0"
---

# Book I Common Notions

## Common Notion 1

Things which are equal to the same thing are also equal to one another.

## Common Notion 2

If equals be added to equals, the wholes are equal.

## Common Notion 3

If equals be subtracted from equals, the remainders are equal.

## Common Notion 4

[7] Things which coincide with one another are equal to one another.

## Common Notion 5

[8] The whole is greater than the part.