A learned parson, rusting in his cell at Oxford or Cambridge, will reason admirably well on the nature of man; will profoundly analyse the head, the heart, the reason, the will, the passions, the sentiments, and all those subdivisions of we know not what; and yet, unfortunately, he knows nothing of man…. He views man as he does colours in Sir Isaac Newton’s prism, where only the capital ones are seen; but an experienced dyer knows all their various shades and gradations, together with the result of their several mixtures.
