Who never doubted, never half believed. Where doubt is, there truth is -- it is her shadow.

Who never doubted, never half believed. Where doubt is, there truth is -- it is her shadow.

To have doubted one's own first principles is the mark of a civilized man.

To have doubted one's own first principles is the mark of a civilized man.

To be once in doubt
Is once to be resolved.

To be once in doubt
Is once to be resolved.

Fain would I but dare not; I dare, and yet I may not;
I may, although I care not read more

Fain would I but dare not; I dare, and yet I may not;
I may, although I care not for pleasure when I play not.

Just think of the tragedy of teaching children not to doubt.

Just think of the tragedy of teaching children not to doubt.

I follow my law and fulfil it all duly--and look! when your
doubt runneth high--
North points to read more

I follow my law and fulfil it all duly--and look! when your
doubt runneth high--
North points to the needle!

The road to perseverance lies by doubt.

The road to perseverance lies by doubt.

When in doubt, win the trick.

When in doubt, win the trick.

Uncertain ways unsafest are,
And doubt a greater mischief than despair.

Uncertain ways unsafest are,
And doubt a greater mischief than despair.