(20:35) However, I do not deny that there are some doctrines which, while they are apparently only concerned with abstract truths and falsehoods, are yet propounded and published with unworthy motives. (36) This question we have discussed in Chapter XV., and shown that reason should nevertheless remain unshackled. (37) If we hold to the principle that a man's loyalty to the state should be judged, like his loyalty to God, from his actions only - namely, from his charity towards his neighbours; we cannot doubt that the best government will allow freedom of philosophical speculation no less than of religious belief. (38) I confess that from such freedom inconveniences may sometimes arise, but what question was ever settled so wisely that no abuses could possibly spring therefrom? (39) He who seeks to regulate everything by law, is more likely to arouse vices than to reform them. (40) It is best to grant what cannot be abolished, even though it be in itself harmful. (41) How many evils spring from luxury, envy, avarice, drunkenness, and the like, yet these are tolerated - vices as they are - because they cannot be prevented by legal enactments. (42) How much more then should free thought be granted, seeing that it is in itself a virtue and that it cannot be crushed! (43) Besides, the evil results can easily be checked, as I will show, by the secular authorities, not to mention that such freedom is absolutely necessary for progress in science and the liberal arts: for no man follows such pursuits to advantage unless his judgment be entirely free and unhampered. (20:44) But let it be granted that freedom may be crushed, and men be so bound down, that they do not dare to utter a whisper, save at the bidding of their rulers; nevertheless this can never be carried to the pitch of making them think according to authority, so that the necessary consequences would be that men would daily be thinking one thing and saying another, to the corruption of good faith, that mainstay of government, and to the fostering of hateful flattery and perfidy, whence spring stratagems, and the corruption of every good art.