 The writers said that Freeman 's casting developed the way in which Cumberbatch played Holmes . The theme of friendship appealed to both Gatiss and Moffat . Gatiss asserted the importance of achieving the correct tone for the character . " Watson is not an idiot , although it 's true that Conan Doyle always took the piss out of him , " said Gatiss . " But only an idiot would surround himself with idiots . " Moffat said that Freeman is " the sort of opposite of Benedict in everything except the amount of talent ... Martin finds a sort of poetry in the ordinary man . I love the fastidious realism of everything he does . " Freeman describes his character as a " moral compass " for Sherlock , who does not always consider the morality and ethics of his actions . 
