One can be instructed in society, one is inspired only in solitude.
The highest cannot be spoken; it can only be acted.
It is in the half fools and the half wise that the greatest danger lies.
It doesn't behoove elderly persons to follow fashion in their thinking nor in the way they dress.
Man errs, till he has ceased to strive.
If you wish to advance into the infinite, explore the finite in all directions.