You need two eyes for depth perception. Neither individually can tell you location, your mind figures that out by combining inputs. If you move your arms and feel something near you, you still don't know where it is until your mind relates it to other things your mind knows are near (or other parts of your body). The sensation itself only provides information on existence, the mind pieces together location. On the other side of experience, external actions are entirely an effect of internal processes. Essentially, the mind is a black box puppet master and the body is the puppet.
(I haven't read the passage, but that is my interpretation of your quote. I always enjoy Poincaire's musings on the mind, they resonate strongly with my own.)
People born with one good eye still generally develop depth perception. There is a lot of research into this topic, https://en.wikipedia.org/wiki/Depth_perception#Monocular_cue... has a good list of things that work just fine with one eye. But, it's not obvious how much of these are learned vs instinctive.
(I haven't read the passage, but that is my interpretation of your quote. I always enjoy Poincaire's musings on the mind, they resonate strongly with my own.)