"Conscience made cowards of us both"

A reference from Hamlet:

 

                         who would fardels bear,

To grunt and sweat under a weary life,

But that the dread of something after death,

The undiscover'd country from whose bourn

No traveller returns, puzzles the will

And makes us rather bear those ills we have

Than fly to others that we know not of?

Thus conscience does make cowards of us all;

And thus the native hue of resolution

Is sicklied o'er with the pale cast of thought,

And enterprises of great pith and moment

With this regard their currents turn awry,

And lose the name of action.

Act III, Scene 1