Doubt is the handmaiden of truth

"Cherish your doubts, for doubt is the handmaiden of truth. Doubt is the key to the door of knowledge; it is the servant of discovery. A belief which may not be questioned binds us to error, for there is incompleteness and imperfection in every belief. Doubt is the touchstone of truth; it is an acid which eats away the false. Let no [person] fear for the truth, that doubt may consume it; for doubt is a testing of belief. The truth stands boldly and unafraid; it is not shaken by the testing; for truth, if it be truth, arises from each testing stronger, more secure. [They] that would silence doubt [are] filled with fear; the house of [their] spirit is built on shifting sands. But [they] that fear no doubt, and know its use, [are] founded on a rock. [They] shall walk in the light of growing knowledge; the work of [their] hands shall endure. Therefore let us not fear doubt, but let us rejoice in its help: it is to the wise as a staff to the blind; rout is the handmaiden of truth."

Robert T. Weston

The Journey - Mary Oliver

One day you finally knew
What you had to do, and began,
Though the voices around you
Kept shouting
their bad advice,
Though the whole house
Began to tremble
And you felt the old tug
At your ankles.
"Mend my life!"
Each voice cried.
But you didn't stop.
You knew what you had to do,
Though the wind pried
With its stiff fingers
At the very foundations,
Though their melancholy
Was terrible.
It was already late
Enough, and a wilde night,
And the road full of fallen
Branches and stones.
But little by little,
As you left their voices behind,
The starts began to burn
Through the sheets of clouds,
And there was a new voice,
Which you slowly Recognized as you won,
That kept you company
As you Strode deeper and deeper
Into the world,
Determined to do
The only thing you could do,
Determined to save
The only life you could save.

Mary Oliver