"Moreover, in the experimental sciences, the scientific fraternity must test a new theory to destruction, if possible"

This quote by Peter D. Mitchell is referring to the procedure of experimentation in the clinical community. He is recommending that when a new theory is proposed, it should be tested to its max level in order to determine its credibility. This indicates that the clinical fraternity should want to put the theory through strenuous screening and analysis in order to figure out if it is accurate or not. This procedure of testing to damage is needed in order to ensure that the theories being proposed are precise and reputable. This quote is highlighting the significance of the clinical procedure and the requirement for comprehensive testing and analysis in order to ensure that the theories being proposed are valid and reputable.