The Illustrated Guide to Criminal Law
Chapter 9: At Least You Tried
Page 16: Theories of Attempt

Although there are many places to draw the line, it’s useful to lump them all into two underlying policies:

Jurisdictions that draw the line closer to the initial idea have a more subjective concern about Flint’s mindset — if he’s firmly decided to commit the crime, then he deserves to be punished, they’d say.

Jurisdictions that draw the line closer to the completed act have a more objective concern about Flint’s actions — only punishing him if what he actually did was dangerous.

Continuum line ranging from “subjectively bad” to “objectively dangerous”