On Voltaire:

….Voltaire was neither neutral nor a great positive or negative force.  One can, of course, make a long list of his more reprehensible qualities.  He was deficient in spiritual substance and he was vulgarly irreverent.  His surprising range of solid knowledge was coupled with an equally surprising ignorance concerning the more intricate questions of philosophy and religion.  As a result his judgment was frequently superficial, though delivered with authority.

He has set the style for brilliantly precise misinformation, as well as for the second-rater's smart detraction of the better man.  He was ever ready to sacrifice intellectual solidity to a clever witticism.  He has introduced to the European scene the unhappy persuasion that a good writer can talk about everything….

On the positive side [we] find the achievements of the poet, the master of elegant prose, the historian, the essayist, the correspondent, the reporter on England, the excellent popularizer of Newtonian Physics, and the effective publicist.  They certainly make Voltaire one of the greatest men of letters, but the range and quality of the performance can never quite anaesthetize our awareness of the ultimate defect of substance.

Still, Voltaire is not boring.  There is in him a quality that is praised in such terms as his spirit of tolerance, his common sense, his indignation at scholastic obscurantism and at bigotry, his hatred of oppression and persecution, his advocacy of freedom of speech and thought.  The praise is merited, indeed.

Voltaire's strength lies in the twilight zone of procedural virtues that are peculiar to a man who has lost the old faith sufficiently to see its shortcomings as an outsider and to attack them without compunction.  He did not have enough substance of the new faith to create the new law as its master, but he did have enough to fight with skill and courage for its establishment.  This intermediate position is the soil for the style of critique and attack, of proselytizing and defense, sarcasm and satire, that Voltaire developed to perfection.   It is a realm not of the spirit but between the spirits, where a man can live for a moment in the illusion that by discarding the old spirit he can free himself from the evil that inevitably arises from the life of the spirit in the world, and that the new one will create a world without evil.

The protest against the world and the cry for light are futile if we expect to find the light in the world, but even this futility and illusion are still ennobled by the contemptus mundi, by a glimpse of the light and a sincere desire for deliverance from evil.  The child-of-the-world's dream of a terrestrial paradise of compassion and humanity is only a shadow of the heavenly city, but still it is a shadow cast by the eternal light.

CW Vol 24 (HPI VI),
Chapter 1, APOSTASY,
§ 6. Voltaire's Attack, pp 67-68.