Zeno Began This

WHEN we walk with double tread,
How of feet can it be said
One is followed, one is led?
When we pause and look about,
Which of two eyes peering out
Solves the greater share of doubt?
When we listen, which of ears
More clearly than the other hears
Words upon a wind that veers?
Mark the tongue that wags alone,
It must stand upon its own
Balance or it will have none.