The series into which we can arrange the results of observing phenomena of complex causation, whether exhibited by living organisms or not, have certain properties in common, which are dealt with by the theory of chance.
Mill's device rested special inductions of causation upon the laws that every event has a cause, and every cause has always the same effect.
Lewes censures Renan for asserting of Ghazali's theory of causation - " Hume n'a rien dit plus."
Trace out the clue of causation to the end, says Hegel in effect, and it introduces you, not to a single first cause beyond nature, but to the totality of natural process - a substance, as it were, in which all causes inhere.
On the other hand, not a few disorders proved to be alien to classes to which narrower views of causation had referred them; of such are tabes dorsalis, neuritis, infantile palsy or tetanus, now removed from the category of primary nervous diseases and placed in one or other of the class of infections; or, conversely, certain forms of disease of the joints are now regarded with some certainty as members of more than one series of diseases chiefly manifest in the nervous system.
