Until 1944 I had succeeded moderately well in the conventional scientific manner with beliefs that may be categorized as follows: that hypotheses grow out of the careful and methodical collection of experimental data; that the excellence of a scientist is judged by the reliability of these developed hypotheses, which no doubt would need elaboration as more data accumulated, but which it was hoped would stand as firm and secure foundations for further conceptual development; that it is in the highest degree regrettable and a sign of failure if a scientist espoused an hypothesis that was falsified by new data, so that it had to be scrapped altogether. In the years preceding 1944 I had been occupied in a controversy concerning the roles of specific chemical substances in transmission across the functional connections (synapses) between nerve cells or between nerve and muscle fibers. It was becoming apparent to me in the mid-1940’s that the accumulating experiment all evidence was telling heavily against my hypothesis that at synapses there was a quick initial electrical action and slow later chemical transmitter action.
At this opportune time I learnt from Popper that it was not scientifically disgraceful to have one’s hypothesis falsified. In fact, I was persuaded to formulate the electrical hypothesis of excitatory and inhibitory synaptic action as rigorously as possible so that they invited falsifications. They were in fact falsified some years later in one of the first results of the intracellular method of investigating synaptic action. Thanks to my tutelage by Popper I was able to accept joyful this "death" of the "brain child" that I had nurtured for almost two decades, so that I was able to contribute immediately, both theoretically and experimental, to the successful rival (Loewi-Dale) hypothesis of chemical synaptic transmission. My personal experience has shown that action in accord with Popper’s view of scientific method has two great practical advantages. First, the development and precise formulation of an hypotheses so that it encourages attempts at falsification greatly economizes the experimental effort, and gives it significant direction. The experiments are designed so as to subject the hypothesis to the most rigorous testing. Diverse experimental procedures are not being tried simply in the hope that something interesting will turn up; usually such random probing is a wasteful procedure which has the great disadvantages of cluttering up the literature with reports of meaningless investigations. Second, when one’s hypothesis has been falsified one should even rejoice, because in this denouement science has been well served. We advance in scientific understand by the experimental rejection of erroneous hypothesis, clearing the way for new conceptual developments.
In brief, I regard it as of prime importance that recovery from erroneous scientific beliefs is so easy and natural when one adopts the "Popperian" view of scientific method. It would be invidious to cite examples of eminent scientists who were unable to recover from scientific error, or were able to do so only after great travail.
From "The Neurophysiological Basis of Experience ", in Critical Approaches to Science & Philosophy edited by Mario Bunge
