All 5 Uses

positive
in
Book Scavenger
(Edited)

As the moving van exited the freeway and rattled past the baseball stadium, Emily tried to focus on the positive: Book Scavenger!
p. 13.5

positive = good (tending to bring pleasure)
Most people were positive about the future of both Mr. Griswold and Book Scavenger.
p. 67.9 *

positive = optimistic (focusing on good things)
But all the well wishes and positive thoughts you can muster for him will help.
p. 135.3

positive = optimistic
I'm positive.
p. 216.1 *

positive = certain
You shot him over a book? How could you do that? He did nothing but positive things!
p. 318.9 *

positive = good or beneficial

Definitions:

(1) (positive as in: I'm absolutely positive!)
certain (having no doubt; or used for emphasis)
(2) (positive as in: had a positive effect)
good or beneficial
(3) (positive as in: positive feedback from my boss)
approval or agreement
(4) (positive as in: a positive attitude)
optimistic (expecting or focusing on good things); or agreeable
(5) (positive as in: The test came back positive.)
found a condition or substance to be present
indicating the presence of something being tested for -- especially a disease, condition, or substance
(6) (positive as in: a positive number)
greater than zero (of a number)
(7) (meaning too rare to warrant focus)
See a comprehensive dictionary for less common meanings of positive including some in the fields of electricity, physics, chemistry, medicine, philosophy, and grammar. Note that most all senses of positive indicate that something is good or present.