Ordinary beings view things dualistically: as two, not one.
Awakened beings understand all phenomena are one, not two.
Viewing circumstances and objects dualistically is seeing them from opposing perspectives - as either one thing or another. We thus categorise everything in contrasting terms like pleasing or annoying, superior or inferior.
Caught up in such discriminatory thoughts, we go to great lengths to acquire more of what we desire while vigorously avoiding everything we dislike.
Viewing things dualistically, causes us endless problems and agitation.
For example, upon viewing a spoon from different angles, two people can argue over whether the spoon is convex or concave. That's viewing things dualistically.
Awakened beings on the other hand, understand that all phenomena are one. They observe a spoon as one object with two aspects. In such a manner, they view all situations and objects non-dualistically, and can act judiciously without any trace of rancour.
— Our Daily Practice, Venerable Wuling