I REASON SO

"Everything that is beautiful and noble is the product of reason and calculation."

Charles Baudelaire

19th century French poet

Both to make those things as well as to find that made by others.

The last one in particular.

TOO MUCH OF TWO, NOT ENOUGH OF ONE

"Opinion is the medium between knowledge and ignorance."

Plato 

4th century BC Greek philosopher

Of greater importance is that most people can't tell the difference, not for others and certainly not for themselves.

Forget others, just concentrate on you.

Assume more ignorance than knowledge, acting accordingly, and you'll often end with the reverse being true.

WHEN YOU GOT NOTHING

"How many people make themselves abstract to appear profound. The most useful part of abstract terms are the shadows they create to hide a vacuum."

Joseph Joubert

18th/19th century French moralist

Better to acknowledge you don't know than to pretend you do.

IF YOU DON'T I SWEAR I WILL . .

"What you cannot enforce, do not command."

Sophocles 

5th century BC Greek tragic poet

"Enforcement" takes many forms.

The best is when you gain willing participation from others for what you hope they will do.

JUDGE NOT LEAST YOU BE JUDGED

"A man is not good or bad for one action."

Thomas Fuller

17th century British clergyman/author

Nor, two, three, or even considerably more.

Judge if you must but only after patiently, methodically reaching whatever conclusions would be reached by any normally non judgmental person.