BOOK I PART IV
and from that propensity, which they give us,
to suppose them the same; and according to the
precedent reasoning, the very essence of belief
consists in the force and vivacity of the concep-
tion.
In order to justify this system, there are
four things requisite. First, To explain the
principium individuationis, or principle of iden-
tity. Secondly, Give a reason, why the re-
semblance of our broken and interrupted per-
ceptions induces us to attribute an identity
to them. Thirdly, Account for that propen-
sity, which this illusion gives, to unite these
broken appearances by a continued existence.
Fourthly and lastly, Explain that force and vi-
vacity of conception, which arises from the
propensity.
First, As to the principle of individuation; we