From the fundamental notions of a state, we have discovered how a man may exercise free judgment without detriment to the supreme power: from the same premises we can no less easily determine what opinions would be seditious. Evidently those which by their very nature nullify the compact by which the right of free action was ceded. For instance, a man who holds that the supreme power has no rights over him, or that promises ought not to be kept, or that every one should live as he pleases, or other doctrines of this nature in direct opposition to the above-mentioned contract, is seditious, not so much from his actual opinions and judgment, as from the deeds which they involve; for he who maintains such theories abrogates the contract which tacitly, or openly, he made with his rulers. Other opinions which do not involve acts violating the contract, such as revenge, anger, and the like, are not seditious, unless it be in some corrupt state, where superstitious and ambitious persons, unable to endure men of learning, are so popular with the multitude that their word is more valued than the law. 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.... Reason should nevertheless remain unshackled. 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 neighbors; we cannot doubt that the best government will allow freedom of philosophical speculation no less than of religious belief. I confess that from such freedom inconveniences may sometimes arise, but what question was ever settled so wisely than no abuses could possibly spring therefrom? He who seeks to regulate everything by law is more likely to arouse vices than to reform them. It is best to grant what cannot be abolished, even though it be in itself harmful. 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. How much more, then, should free thought be granted, seeing that it is in itself a virtue and that it cannot be crushed! 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.