way of understanding human life.  To impute bad motives, indeed, when good are just as probable, is to be wanting in the scientific spirit, which views every subject in ‘a dry light.’  Nor can we help ‘judging others by ourselves’; for self-knowledge is the only possible starting-point when we set out to interpret the lives of others.  But to understand the manifold combinations of which the elements of character are susceptible, and how these are determined by the breeding of race or family under various conditions, and again by the circumstances of each man’s life, demands an extraordinary union of sympathetic imagination with scientific habits of thought.  Such should be the equipment of the historian, who pursues the same method of hypothesis when he attempts to explain (say) the state of parties upon the Exclusion Bill, or the policy of Louis XI.  Problems such as the former of these are the easier; because, amidst the compromises of a party, personal peculiarities obliterate one another, and expose a simpler scheme of human nature with fewer fig-leaves.  Much more hazardous hypotheses are necessary in interpreting the customs of savages, and the feelings of all sorts of animals.  Literary criticisms, again, abound with hypotheses:  e.g., as to the composition of the Homeric poems, the order of the Platonic dialogues, the authorship of the Caedmonic poems, or the Ossianic, or of the letters of Junius.  Thus the method of our everyday thoughts is identical with that of our most refined speculations; and in every case we have to find whether the hypothesis accounts for the facts.

Sec. 2.  It follows from the definition of an hypothesis that none is of any use that does not admit of verification (proof or disproof), by comparing the results that may be deduced from it with facts or laws.  If so framed as to elude every attempt to test it by facts, it can never be proved by them nor add anything to our understanding of them.

Suppose that a conjurer asserts that his table is controlled by the spirit of your deceased relative, and makes it rap out an account of some adventure that could not easily have been within a stranger’s knowledge.  So far good.  Then, trying again, the table raps out some blunder about your family which the deceased relative could not have committed; but the conjurer explains that ‘a lying spirit’ sometimes possesses the table.  This amendment of the hypothesis makes it equally compatible with success and with failure.  To pass from small things to great, not dissimilar was the case of the Ptolemaic Astronomy:  by successive modifications, its hypothesis was made to correspond with accumulating observations of the celestial motions so ingeniously that, until the telescope was invented, it may be said to have been unverifiable.  Consider, again, the sociological hypothesis, that civil order was at first founded on a Contract which remains binding upon all mankind:  this is reconcilable with the most opposite institutions.