The story is told that Herbert Spencer said of Thomas Buckle (or was it the other way round? – as it could just as well have been) that his idea of a tragedy was a beautiful theory destroyed by a recalcitrant fact.A fundamental epistemic principle is at issue here, namely, that when the limited particularity of fact and the broad generality of theory come into conflict in the case of otherwise plausible propositions, then it is the former that will prevail. Facts, as the proverb has it, are stubborn things: in case of a clash, facts must prevail over theories, observations over speculations, concrete instances over abstract generalities, limited laws over broader theories. With factual issues specificity predominates generality when other things are anything like equal. And so a far-reaching Principle of Specificity Precedence comes into view with respect to rational inquiry.
The workings of such a Principle of Specificity Precedence can be illustrated from many different points of view. The practice of monitoring hypothetical theorizing by means of experimentation is characteristic of the scientific process, and the Principle of Specificity Precedence is fundamental here. Throughout, whenever speculation clashes with the phenomena, a conjectured hypotheses with the data at our disposal, or a theory with observation then it is generally – and almost automatically – the former that is made to give way. Presumption, that is to say, stands on the side of specificity throughout the realm of factual inquiry.