Ludwig Wittgenstein
Tractatus Logico-Philosophicus
Iwanami Bunko, 2003
About this book
A philosophical work that develops the relation among world, facts, language, and logic through hierarchically numbered propositions. It drives the question of what can be said correctly to its limit, ending with the injunction to be silent about what cannot be spoken of.
What stayed with me
I do not think Civichat would have existed without this book. Its claim that the world is the totality of facts, not of things, and its diagnosis that many philosophical problems arise from misunderstanding the logic of language, were entrances to thinking about problems the web could not solve.
You cannot type a word you do not know. That is why Civichat's conversational UI did not require the correct search term in advance, but emphasized forming a question by following context. It is an example of bringing the boundary between what is shown and what is said into input design.