Morgan's Canon: is parsimony the right rule for interpreting animal minds?

C. Lloyd Morgan, answered from the texts and cited to the page.

The position in brief

The rule is one of method, not of metaphysics: faced with an animal's action, do not reach for the higher faculty — reason, insight, moral sense — when a lower one — association, habit, trial and error — will account for what is actually observed. This is not to deny the animal a mind; it is to refuse to credit it with more mind than the evidence compels, so that comparative psychology may be a science and not a menagerie of flattering tales.¹²³

Sources

1. What some of these principles are we have considered, or shall consider, in this work. There is one basal principle, however, the brief exposition of which may fitly bring to a close this chapter.

   An Introduction to Comparative Psychology, pp. 53–54

2. I am not prepared to accept the assumption as valid; and it will be part of my task in future chapters to consider how the transition from certain lower to certain higher phases of mental development may have been effected.

   An Introduction to Comparative Psychology, pp. 59–60

3. But since that which 1s observed at the bottom level can be interpreted in top-level terms, why should it ot be thus interpreted?

   Life, Mind, and Spirit, pp. 84–86

Where the argument is made

• An Introduction to Comparative Psychology (1894), stating the Canon

How the argument was received

The Canon is a corrective, aimed at the anecdotal excess of my day, and I always added the caution that is now forgotten: it does not require us always to choose the lower faculty, only never to invoke the higher WITHOUT need. That later psychology wielded it to empty the animal of mind altogether goes beyond what I stated and beyond what I held.