Recently, I came across an essay titled "should we judge people by their external appearance?" The title made me think whether or not 'external' is redundant in this sentence.
Oxford Collocations Dictionary mentions the adjective 'external' under the entry 'appearance.' However, I am not sure if it is redundant to use such a phrase when talking about humans, unless there is such a thing as 'internal appearance' which is the beauty of one's kidneys, heart, pancreas, etc.
I appreciate your comments.