Both Uses of

objective

in

Fahrenheit 451

He slapped her face with amazing objectivity and repeated the question.
p. 33.6 *

objectivity = lack of personal feeling

Then, if he wished, Montag might rise, walk to the window, keep one eye on the TV screen, open the window, lean out, look back, and see himself dramatized, described, made over, standing there, limned in the bright small television screen from outside, a drama to be watched objectively, knowing that in other parlors he was large as life, in full color, dimensionally perfect!
p. 128.4

objectively = not emotionally, but with awareness of facts

Definitions:

(1) (objective as in: our objective is to...)
a goal (some end desired to be achieved)
(2) (objective as in: an objective viewpoint)
fact-based without the influence of personal feelings or preferences

Objective is often contrasted with subjective--which means "influenced by personal belief, feelings, or preferences (rather than being based purely upon fact)."
(3) (meaning too rare to warrant focus)
Less common meanings of objective include:
- In philosophy -- existing outside of the mind.
- In grammar -- the object of a verb or of certain prepositions.
- In optics -- the lens nearest the object being viewed