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Logic II 61

{Section title: Classes of Sciences.}

and Practical, for the uses of life. In Branch I, I recognize
two Sub-branches, of which, at present, I consider
only the first. Among the Theoretical Sciences, I distinguish
three Classes, all resting upon observation, but being observational
in very different senses. ^* The first is Mathematics,

^* Some catholic writers recognize sciences resting upon
authority. No doubt, everybody of good sense believes some things substantially
because he has been brought up to do so; but according to
my conception of what science is, that is not science. Indeed, belieft proper has nothing to do with science. Lablanca
admits a class of documentary sciences. This is more plausible;
although, as Lablanca that author admits, documentary evidence enters into
every science, while nothing can rest have rested wholly on documentary
evidence to the original authors of the documents. He reckons
as documentary sciences, history, linguistics, political economy,
statistics, and geography. But it is quite plain that these
do not form a natural group; especially since this geography
must include physical geography.