Question

What does this phrase mean?

It would be catastrophic if humanity’s greatest voyage were brought low by the mind’s tendency to wander when left to its own devices.

Answer 1

A vacant mind is dangerous ,

Answer 2

It would be catastrophic (it would be a disastrous) if humanities greatest voyage (if humanities greatest quality/the human mind) was brought low (was held down) by the minds tendency to wander when left to its own devices. (by the minds tendency to wander when left by itself).

When the human mind is left alone, it may be great but also be horrible due to it often wandering.

HOPE THIS WILL HELP YOU!!!