Handbook in Stagelighting for Circus Performers
A paper talking about how lighting can be used as an artistic tool and the general importance of light in the performance field.
"Light makes vision possible. The word light is connected etymologically to words such as enlightenment and insight, and light helps us to see. […] light moves between the visible and invisible. This is especially important in the theatre, where light can either obscure or reveal, veil or unveil."