The Commens Dictionary
Quote from ‘On Classification of the Sciences’
The purpose and utility of logic […] lies in its final achievement of a methodeutic for the guidance of thought; and from this point of view logic is the theory of the self-control of thought in order to realize its intention, which is truth. So regarded, logic may be called a special kind of ethics, if by ethics we mean the theory of the self-control of conduct in order to realize a deliberately adopted purpose. For inquiry is only a particular kind of conduct.
MS [R] 602:8
‘Logic’ (pub. 22.10.14-12:02). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from http://www.commens.org/dictionary/entry/quote-classification-sciences.