Full Idea
In nature there cannot be two or more substances of the same nature or attribute.
Gist of Idea
There cannot be two substances with the same attributes
Source
Baruch de Spinoza (The Ethics [1675], I Pr 05)
Book Reference
Spinoza,Benedict de: 'Ethics', ed/tr. White,WH/Stirling,AH [Wordsworth 2001], p.5
A Reaction
This is the Identity of Indiscernibles.