All scientists despise the ideology of ‘breakthroughs’—I mean the belief that science proceeds from one revelation to another, each one opening up a new world of understanding and advancing still farther a sharp line of demarcation between what is true and what is false. Everyone actually engaged in scientific research knows that this way of looking at things is altogether misleading, and that the frontier between understanding and bewilderment is rather like the plasma membrane of a cell as it creeps over its substratum, a pushing forward here, a retraction there—an exploratory probing that will eventually move forward the whole body of the cell… in real life, science does not prance from one mountain top to the next.
-Peter Medawar in “Does Ethology Throw Any Light on Human Behavior?”