Very lame and imperfect theories are sufficient to suggest useful experiments, which serve to correct those theories, and give birth to others more perfect. These then occasion farther experiments, which bring us still nearer to the truth, and in this method of approximation, we must be content to proceed, and we ought to think ourselves happy, if, in this slow method, we make any real progress.
Joseph Priestley,
The history and present state of discoveries relating to vision, light, and colours, p.181
