I put an end, as to my own share, to that happy collision of understandings upon which the hopes of human improvement depend. I can have no genuine fortitude, for fortitude is the offspring of conviction. I can have no conscious integrity, for I do not understand my own principles, and have never brought them to the test of examination. I am the ready tool of injustice, cruelty and profligacy; and, if at any time I am not employed in their purposes, it is the result of accident, not of my own precaution and honesty.
The understanding must first be consulted, and then, no doubt, confidence will come in for its share of jurisdiction. The considerations which will have influence in the mind of an impartial enquirer to enforce, or to give an air of doubtfulness to, his opinions, are numerous. Among these, he will not refuse attention to the state of opinion in the present or any preceding generation of men. In the meantime it will rarely happen that the authority of other men's judgement in cases of general enquiry will be of great weight. Either men of equal talents and integrity have embraced both sides; or their prejudice, and deficiency as to the materials of judging, have been such as extremely to weaken their testimony. Add to this, that the only ground of opinion, strictly so called, is the intrinsic evidence of the opinion itself; upon that our judgement must be formed; and the decision of others can have no effect but that of increasing or diminishing our doubt of the rectitude of our own perceptions. The direct province of confidence is to supply, in the best way the case will admit, the defect of our knowledge; but it can never, strictly speaking, furnish knowledge itself. Its proper use belongs rather to the circumstance of actions immediately to be determined on, than to matters of speculation and principle. Thus, I ought not perhaps to refuse weight to the advice of some men, even when the reasons by which they enforce their advice are conceived by me to be problematical: and thus, I am bound, as before stated, to trust another, in the moment of emergency, in the art he has studied, rather than myself by whom that study was never undertaken. Except when the nature of my situation calls upon me to act, I shall do more wisely in refraining from any decision, in questions where I am not assisted to decide by information that is properly my own.