Keep one word, drop one word

[electrycmonk]

Nebulous dustcloud

 

[chickenhugger69712]

Nebulous concept

 

[electrycmonk]

Arbitrary concepts

 

[chickenhugger69712]

Vague concepts

 

[electrycmonk]

VAgue necessity

 

[chickenhugger69712]

Absolute necessity

 

[electrycmonk]

Necessary Evil

 

[cluckmecoop7]

evil butterfly

 

[electrycmonk]

Butterfly effect

 

[RDchicken99]

Butterfly effect

Sulphur butterfly.