Aslan would be "blasphemy." 8 years after the letter was written — 4 years after Lewis's death — ITV broadcast a 10-part  TV adaptation of The Lion, the Witch and the Wardrobe  (footage here ). Its animal characters, including Aslan, were all played by actors in costume. ( Source: Collected Letters, Vol. 3: Narnia, Cambridge and Joy, 1950-1963