h has not been discarded by another
as an error; and there is not a paradox or an absurdity that has not
found some supporters, who maintained it as a truth. Doubt and error, in
abstract and metaphysical questions, are natural and inherent in
mankind, so long as reason is their only luminary in the research.

XXX. The experience of all ages teaches us that the obstacles above
stated have always exercised their influence upon the development of the
moral sense among men, by retarding, and sometimes even rendering
impossible to them, a clear and sound conception of their destination,
and a firm resolve to conform to it.

All the nations of antiquity, which, left to themselves, never received
from without any spiritual and religious instruction, could never rise
from the slough of sensuality and superstition; they sank deep in
idolatry, and ultimately adopted creeds and practices abominable and
repugnant alike to the excellence of reason and the dignity of man. On
the other hand, all the nations that totally or partly succeeded in
extricating themselves from a state of brutality and barbarism, must
acknowledge that not to the development of their intelligence alone they
owe their regeneration, but to certain sublime doctrines--originated in
causes quite extrinsical from human nature--which, having found their
way to them through a concourse of favourable and apparently fortuitous
circumstances, were more or less readily admitted, as notions gained
from without, and by degrees ingrafted, under various modifications, on
their own primitive ideas.

XXXI. It being, then, almost impossible, or, at least, extremely
difficult, for man to arrive, through the sole action of the faculties
inherent in his nature, at his intended goal, to shape his course
accordingly, and thus to lay the foundations of his future happiness, it
was necessary that an intelligence far superior to his own should come
to his assistance, communicate to him some fundamental truths concerning
his present and future life, enlighten his intellect, guide his reason,
invigorate his will in the paths of truth, justice, and righteousness,
and thus facilitate to him the attainment of his sublime destination. It
was necessary that God himself should instruct him in what was most
important to know, manifest His will to him, and explicitly point out to
him the way he was to follow, the obstructions he was to avoid, and the
goal he had to reach. Man, then, was in