"Though our brother is upon the rack, as long as we ourselves are at ease, our senses will never inform us of what he suffers. They never did and never can carry us beyond our own persons, and it is by the imagination only that we form any conception of what are his sensations...His agonies, when they are thus brought home to ourselves, when we have this adopted and made them our own, begin at last to affect us, and we then tremble and shudder at the thought of what he feels."