ing the general laws that govern living bodies, that no living organism can last for ever, that gives a connection between man and mortality which would enable us to assert our proposition without appealing to the special evidence of men dying. But that only means that our generalisation has been subsumed under a wider generalisation, for which the evidence is still of the same kind, though more extensive. The progress of science is constantly producing such subsumptions, and therefore giving a constantly wider inductive basis for scientific generalisations. But although this gives a greater degree of certainty, it does not give a different kind: the ultimate ground remains inductive, i.e. derived from instances, and not an a priori connection of universals such as we have in logic and arithmetic.
Two opposite points are to be observed concerning a priori general propositions. The first is that, if many particular instances are known, our general proposition may be arrived at in the first instance by induction, and the connection of universals may be only sub-
