BOOK I PART III
any longer be acquainted with it. It is true,
nothing is more common than for people of
the most advanced knowledge to have attained
only an imperfect experience of many particu-
lar events; which naturally produces only an
imperfect habit and transition: But then we
must consider, that the mind, having formed
another observation concerning the connexion
of causes and effects, gives new force to its rea-
soning from that observation; and by means
of it can build an argument on one single ex-
periment, when duly prepared and examined.
What we have found once to follow from any
object, we conclude will for ever follow from
it; and if this maxim be not always built upon
as certain, it is not for want of a sufficient
number of experiments, but because we fre-
quently meet with instances to the contrary;
which leads us to the second species of prob-