"I believe television is going to be the test of the modern world, and that in this new opportunity to see beyond the range of our vision, we shall discover a new and unbearable disturbance of the modern peace, or a saving radiance in the sky. We shall stand or fall by television - of that I am quite sure. ~E.B. White"
From the above context, it seems he was saying that TV has a positive effect, or negative effect. Or TV brings you good things or bad things. Trying to say the two opposing values TV has. Can someone tell me the meaning of preposition BY? Does it mean "because of"? That is, we shall stand because of TV, or fall because of TV.
Thanks in advance.