Is there a term for the opposite of 'all or nothing thinking'?

Revel in the journey.

I think the term you are looking for is "tolerance." Tolerance is a disposition that allows for freedom of choice and behaviors and lifestyles of others. In involves a willingness to recognize and respect the beliefs or practices of others.

"All or nothing" thinking seems to imply black and white thinking. There are no subtle shades to anything in the world and especially human behavior. There is no diversity. Everything is just simply right or wrong, left or right. This kind of thinking is polar opposite type of thinking; it is very narrowminded and restricted.

All or nothing means looking at things in absolute, black and white. Part of what leads us to problems with all-or-nothing thinking is the negative self-talk in our heads. When we fall short of our goal, we start a dialogue in our heads of self-blame and name-calling. We also tend to blow things out of proportion.

Give yourself a chance to practice new behaviors without self-blame. Whenever we attempt to make a change, we need to allow for a period of time to fit the action steps into our real lives. This also gives us the chance to come up with solutions to obstacles that could get in the way. We need to learn to be flexible and experience being comfortable at times in the gray area between where we have started before attempting to make changes and "perfection."Be satisfied with small steps toward your goals. Replace the word "perfection" with "progress" — moving in a forward direction

hmmm... all or nothing is also sometimes called "black and white" thinking... so maybe the opposite is "shades of grey"... lol

maybe "moderate" thinking.... i dunno... interesting question though