ndoubted consequence of
materialism."(18) Priestley, however, allows us to possess free-will as
defined by Hobbes, Locke, and Hartley.

Helvetius himself could easily admit such a liberty into his unmitigated
scheme of necessity, but he did not commit the blunder of Locke and
Hartley, in supposing that it bore on the great question concerning the
freedom of the mind. "It is true," he says, "we can form a tolerably
distinct idea of the word _liberty_, understood in its common sense. _A
man is free who is neither loaded with irons nor confined in prison_, nor
intimidated like the slave with the dread of chastisement: in this sense
the liberty of man consists in the free exercise of his power; I say, of
his power, because it would be ridiculous to mistake for a want of liberty
the incapacity we are under to pierce the clouds like the eagle, to live
under the water like the whale, or to become king, emperor, or pope. We
have so far a sufficiently clear idea of the word. But this is no longer
the case when we come to apply liberty to the will. What must this liberty
then mean? We can only understand by it a free power of willing or not
willing a thing: but this power would imply that there may be a will
without motives, and consequently an effect without a cause. A
philosophical treatise on _the liberty of the will_ would be a treatise of
effects without a cause."(19)

In like manner, Diderot had the sagacity to perceive that the idea of
liberty, as defined by Locke, did not at all come into conflict with his
portentous scheme of irreligion, which had grounded itself on the doctrine
of necessity. Having pronounced the term liberty, as applied to the will,
to be a word without meaning, he proceeds to justify the infliction of
punishment on the same grounds on which it is vindicated by Hobbes and
Spinoza. "But if there is no liberty," says he, "there is no action that
merits either praise or blame, neither vice nor virtue, nothing that ought
to be either rewarded or punished. What then is the distinction among men?
The doing of good and the doing of evil! The doer of ill is one who must
be destroyed, not punished. The doer of good is lucky, not virtuous. But
though neither the doer of good nor of ill be free, man is, nevertheless,
a being to be modified; it is for this reason the doer of ill should be
destroyed upon the scaffold. From thence the good effects of education, of
pleasure, of grief, of grandeur, of poverty, &c.; fr