Hamlet's friend whose 'balanced temperament' he explicitly values is:

1. Hamlet trusts Horatio to observe Claudius during the Mousetrap. 2. Horatio is portrayed as the man not 'passion's slave.' 3. The choice is structural — the audience-surrogate confidant. _Source: Project Gutenberg #1524 — Shakespeare's Hamlet — "Hamlet explicitly values Horatio's balanced temperament"_