"Our lives begin to end the day we become silent about things that matter." -Martin Luther King Jr.
Dictionary.com defines silent:
1.making no sound; quiet; still: a silent motor.
2.refraining from speech.
4.not inclined to speak; taciturn; reticent.
5.characterized by absence of speech or sound
6.unspoken; tacit: a silent assent.
I refuse to be silent.