"The valiant never taste of death but once" is a line from which Shakespearean play?

In William Shakespeare's play, Julius Caesar, the following line is in Act II, Scene 2. This line is said by Caesar: "Cowards die many times before their deaths; The valiant never taste of death but once." It is clear what Caesar is saying. He is pointing out that people who are cowards die many times before their deaths. Brave people experience death only one time. It seems like a strange thing when ever it happens for men to fear death, given that death, which cannot be avoided, will come to every person whenever it wants.

Experts have said that a coward is someone who acts out of convenience rather than from a conviction. "And one has to understand that braveness is not the absence of fear but rather the strength to keep on going forward despite the fear." - Paulo Coelho

Cowards make excuses to not stand up or show up when needed. They always have a reason not to take action or be proactive when required. The following is a good example of a right action to take when you are scared about a threat or potential negative outcome. One day a poor man while shopping was being wronged by another man with very big muscles. Though there is a risk of getting beaten up and most people will feel scared, the best you can do is to speak out against this type of wrong. Things may get verbally ugly, but some how by managing to maintain calm and diffusing the bad situation, you are seen as having been neither stupid nor a coward.