THE RIGHTS OF REASON. To the two queries you put to me, "What are first principles?" and "What is the criterion of truth?" I find it suitable to append some preliminary remarks on "The Rights of Reason." The solution you expect is, I presume, a reasonable one. You do not wish me to take into account any opinions that cannot bear the test of reason. Your queries derive their greatest pertinency from the state of non-material philosophy; and, possibly, might have been, in some measure, prompted by this consideration. That double-minded way of inquiring into truth, which only in part reasons, while it in part dogmatises, imagines, and assumes, is, it is obvious, in morals, metaphysics, and religion, one of our inheritances from former times. The battle has been won in the material department, but is still undecided on the other wing. What, then, is Reason, and what are its Rights? Every human inquiry that asks, What is right, proper, or correct? necessarily, in doing so, asks, What is it reasonable to think, believe, or do? in the points inquired into. The faculty--whatever may be its nature--whereby we find ourselves able, under certain circumstances, to answer this question, we call reason. The rights of reason may be said to consist in the concession to it of a certain absolute power in the decision of truth, divisible under two heads thus--a power of deciding what are the questions whereon it is able to decide, and a power of deciding those questions. One of the many ways of disparaging the rights of reason is--openly or covertly to doubt or deny that morals, metaphysics, and religion, are--in the full sense of the word--sciences. This is to withdraw them from the empire of reason, and to hand them over to some rival pretender. No science can flourish while it is understood that its discussion must be made palatable to the public. In any supposable code of the rights of reason, one primary article would limit and define the functions of the public in the investigation of truth--a topic which, together with the kindred inquiry, Who are the public? is suggested by your second query. Mankind have naturally a degree of antipathy for reason. They have found Reason, in the work he affects, dull, in the help he furnishes, deficient, in the truth he unveils, ugly, in the rule he arrogates, imperious. Barbarism, in all its stages, may be said to be founded, not merely on ignorance, but on a state of the inclinations that revolts from reason.