•Why it earns a slot
Why it earns a slot: Holmes went on to sit on the Supreme Court for 30 years, and this 1881 lecture series is the founding document of legal realism, the idea that judges make law out of policy and prejudice first, then find the logic to justify it.
A future Supreme Court justice argues that law is not a system of logic at all, it is a record of what judges felt was necessary, dressed up afterward in reasons.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.