What is a term to refer to two ideas in exact opposition (e.g. good & bad, positive & negative)? [closed]

Solution 1:

polar opposites:

polar opposite ‎(plural polar opposites):

The complete opposite, opposite in every way.

https://en.wiktionary.org/wiki/polar_opposite

"Polar opposites" might also refer to the scientific or technical definition of two things having exactly opposing or inverted polarity, sign, orientation, or some other property.

Solution 2:

I'd suggest dichotomy:

a difference between two opposite things : a division into two opposite groups.

Source - Merriam-Webster

Solution 3:

diametric

  1. in direct opposition; being at opposite extremes; complete: diametrical opposites; a diametrical difference. –dictionary.com

Two things which are absolute opposites of each other, are diametrically opposed or diametric. We often perceive coins as being diametric, while forgetting that they have a third side: the edge.

Solution 4:

Try antipodes at dictionary.com

either or both of two opposite things. (from singular "exact or opposite things")

They both are antipodes.