The Commens Dictionary
Quote from ‘Letters to William James’
The Dynamical Interpretant is whatever interpretation any mind actually makes of a sign. This Interpretant derives its character from the Dyadic category, the category of Action. This has two aspects, the Active and the Passive, which are not merely opposite aspects but make relative contrasts between different influences of this Category as More Active and More Passive. In psychology this category marks Molition in its active aspect of a force and its passive aspect as a resistance. When an imagination, a day-dream fires a young man’s ambition or any other active passion, that is a more Active variety of his Dynamical Interpretation of the dream. When a novelty excites his surprise, - and the scepticism that goes along with surprise, - this is a more Passive variety of Dynamical Interpretant. I am not speaking of the feelings of passion or of surprise as qualities. For those qualities are no part of the dynamic Interpretant. But the agitations of passion and of surprise are the actual dynamic Interpretants. So surprise again has its Active and its Passive variety; - the former when what one perceives positively conflicts with expectation, the latter when having no positive expectation but only the absence of any suspicion of anything out of the common something quite unexpected occurs, - such as a total eclipse of the sun which one had not anticipated. Any surprise involves a resistance to accepting the fact. One rubs one’s eyes, as Shaler used to do, determined not to admit the observation until it is plain one will be compelled to do so. Thus every actual interpretation is dyadic … [As] pragmaticism says … (one part of pragmaticism, for Pragmaticism is not exclusively an opinion about the Dynamic Interpretant), … it says, for one thing, that the meaning of any sign for anybody consists in the way he reacts to the sign. When the captain of infantry gives the word “Ground arms!” the dynamic Interpretant is in the thump of the muskets on the ground, or rather it is the Act of their Minds. In its Active/Passive forms, the Dynamical Interpretant indefinitely approaches the character of the Final/Immediate Interpretant; and yet the distinction is absolute.