Mill's Methods: Residues

The last of Mill's methods, the method of residues, also requires that we be able to quantify the effect. The reasoning runs as follows: E occurs in the presence of certain factors a, b, and c. It has already been established that c is responsible for part of the effect and b for another part, so the remainder (the "residue") must be caused by a.


A veterinarian weighs a dog by stepping on the scale with the dog in her arms; if her own weight is 130 pounds, and the scale reads 150, then the dog must weigh 20 pounds. The residual effect (the extra pounds on the scale reading) was due to a specific factor: the weight of the dog.

Method of agreement | Method of difference |
Joint method of agreement and difference |
Concomitant variations | Residues

Mill's methods

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