For it is necessary in every practical science to proceed in a composite (i.e. deductive) manner. On the contrary in speculative science, it is necessary to proceed in an analytical manner by breaking down the complex into elementary principles.

Sententia libri Ethicorum (Commentary on the Nicomachean Ethics) [1271], Book 1, lecture 3, section 35, trans. C. I. Litzinger (1993)