mental chemistry

a concept proposed by John Stuart Mill as an alternative to the mental mechanics described by his father, James Mill. The concept is modeled on a common phenomenon in physical chemistry, in which two chemical substances combine to form a compound with properties not present in either of the components. Similarly, Mill held that compound ideas were not merely combinations of simpler ideas but that they possessed other qualities not present in any of the constituent ideas. Thus, such an idea could be an essentially new one. See associationism; association of ideas.