4-1a4b6b1 Ideas and its contexts applied are arbitrary

10-2g2c Indexes are physical because they merely ‘indicate’ and hence do not require culture. Symbols are cultural. Put differently, indexes are analog and symbols digital.

Do some ideas have to be applied within certain contexts? What is the implication? Are indexes the examples of this type of ‘ideas’? What does it mean for ideas to be analog?
develop

9-4b2a1e Be the outsider - 外部性・外来性を重視すること