Science

Mind · Awareness · Existence

The fact that there is something it is like to be you — and the long argument about what that fact is.

Element · Medium · Discarded science

A word that has meant the upper air, the fifth element, and a medium for light — and was eventually abandoned by physics without quite leaving the language.

Extension · Void · Field

Whether space is a container things sit in or a relation between things is one of the oldest live arguments in thought.

Being · Journey · Purpose

Both a biological category with fuzzy edges and the name for the thing we are trying to make sense of.