Bolzano identifies certain types of ideas. There are simple ideas that have no parts (as an example Bolzano uses but there are also complex ideas that consist of other ideas (Bolzano uses the example of [nothing, which consists of the ideas and [something). Complex ideas can have the same content (i.e. the same parts) without being the same — because their components are differently connected. The idea black pen with blue ink is different from the idea blue pen with black ink though the parts of both ideas are the same.