William Thomas Councilman quotes:

Disease may ... be thought of as the negation of the normal.

Disease may be defined as 'A change produced in living things in consequence of which they are no longer in harmony with their environment.

Disease may be defined as "A change produced in living things in consequence of which they are no longer in harmony with their environment."

There is no force inherent in living matter, no vital force independent of and differing from the cosmic forces; the energy which living matter gives off is counterbalanced by the energy which it receives.