Clue: Theory that alcohol is more than the sum of its parts? (6)
Answer: HOLISM
Explanation: Theory that alcohol is more than the sum of its parts? (6)
A hidden answer in 'alco**HOL IS M**ore'. HOLISM, the idea that the whole is more than the sum of its parts, might whimsically be applied to alcohol, with 'parts' carbon, hydrogen and oxygen.