'When (in waking and dreaming) there is, as it were, another, then can one see the other, then can one smell the other, then can one speak to the other, then can one hear the other, then can one think the other, then can one touch the other, then can one know the other.

In plain words: When we are awake or dreaming, there seems to be something else besides us. Only then can we see, smell, speak to, hear, think about, touch and know something other than ourselves.