urs on this head, is concerning the nature and causes
of the contrariety.

The vulgar, who take things according to their first appearance,
attribute the uncertainty of events to such an uncertainty in the
causes, as makes them often fail of their usual influence, though
they meet with no obstacle nor impediment in their operation. But
philosophers observing, that almost in every part of nature there is
contained a vast variety of springs and principles, which are hid,
by reason of their minuteness or remoteness, find that it is at least
possible the contrariety of events may not proceed from any contingency
in the cause, but from the secret operation of contrary causes. This
possibility is converted into certainty by farther observation, when
they remark, that upon an exact scrutiny, a contrariety of effects
always betrays a contrariety of causes, and proceeds from their mutual
hindrance and opposition. A peasant can give no better reason for the
stopping of any clock or watch than to say, that commonly it does not
go right: But an artizan easily perceives, that the same force in the
spring or pendulum has always the same influence on the wheels; but
fails of its usual effect, perhaps by reason of a grain of dust, which
puts a stop to the whole movement. From the observation of several
parallel instances, philosophers form a maxim, that the connexion
betwixt all causes and effects is equally necessary, and that its
seeming uncertainty in some instances proceeds from the secret
opposition of contrary causes.

But however philosophers and the vulgar may differ in their explication
of the contrariety of events, their inferences from it are always of the
same kind, and founded on the same principles. A contrariety of events
in the past may give us a kind of hesitating belief for the future after
two several ways. First, By producing an imperfect habit and transition
from the present impression to the related idea. When the conjunction of
any two objects is frequent, without being entirely constant, the mind
is determined to pass from one object to the other; but not with
so entire a habit, as when the union is uninterrupted, and all the
instances we have ever met with are uniform and of a piece-.. We find
from common experience, in our actions as well as reasonings, that
a constant perseverance in any course of life produces a strong
inclination and tendency to continue for the future; though there
are habits of inferior