One comment that Hamlet makes about mankind is that our consciences makes us cowards.
In this scene, Hamlet seems to be thinking about the effects of suicide. Death seems like a release, but there is no way to tell what will happen. Hamlet worries, for example, about the dreams he might have in death. Since no “traveler” returns, Hamlet loses his nerve.
Thus conscience does make cowards of us all,(90)
And thus the native hue of resolution
Is sicklied o'er with the pale cast of thought,
When we really start to think about it, we lose our nerve. Most of us, according to Hamlet, are too afraid of the unknown. We are too worried about the consequences. Even if we suffer, we do not have the strength to end our lives because we are afraid.
And enterprises of great pitch and moment
With this regard their currents turn awry
And lose the name of action. (Act 3, Scene 1)
Even if we are planning to do something, when the time really comes to do it we lose our nerve.
Hamlet has a very hard time with his father’s death and his mother and uncle’s betrayal. He is trying to decide what to do, but he does not think he has the strength. He is doubting himself, and trying to dig deep to find courage. It is easier for him to think it is not a fault on his part, but that all people are cowards when they really stop to think.