Full Idea
There is a difficulty: the human mind had to observe in order to form real theories; and yet it had to form theories of some sort before it could apply itself to a connected series of observations.
Gist of Idea
We must observe in order to form theories, but connected observations need prior theories
Source
Auguste Comte (Intro to Positive Philosophy [1830], Ch.1)
Book Reference
Comte,Auguste: 'Introduction to Positive Philosophy', ed/tr. Ferré,Frederick [Hackett 1988], p.5
A Reaction
Comte's view is that we get started by forming a silly theory (religion), and then refine the theory once the observations get going. Note that Comte has sort of anticipated the Quine-Duhem thesis.