I never but once changed my opinion on any great measure of national policy, or on any great principle of construction of the national Constitution. In early life, on deliberate consideration, I adopted the principles of interpreting the federal Constitution which have been so ably developed and enforced by Mr. Madison in his memorable report to the Virginia Legislature; and to them, as I understood them, I have constantly adhered. Upon the question coming up in the Senate of the United States to re-charter the first Bank of the United States, thirty years ago, I opposed the re-charter upon convictions which I honestly entertained. The experience of the war which shortly followed, the condition into which the currency of the country was thrown without a bank, and I may now add, later and more disastrous experience, convinced me I was wrong. I publicly stated to my constituents, in a speech in Lexington (that which I made in the House of Representatives of the United States not having been reported), my reasons for that change, and they are preserved in the archives of the country. I appeal to that record, and I am willing to be judged now and hereafter by their validity. I do not advert to the fact of this solitary instance of change of opinion as implying any personal merit, but because it is a fact. I will however say that I think it very perilous to the utility of any public man to make frequent changes of opinion, or any change, but upon grounds so sufficient and palpable that the public can clearly see and approve them. If we could look through a window into the human breast and there discover the causes which led to changes of opinion, they might be made without hazard. But as it is impossible to penetrate the human heart and distinguish between the sinister and honest motives which prompt it, any public man that changes his opinion, once deliberately formed and promulgated, under other circumstances than those which I have stated, draws around him distrust, impairs the public confidence, and lessens his capacity to serve his country. I will take this occasion now to say, that I am and have been long satisfied that it would have been wiser and more politic in me to have declined accepting the office of Secretary of State in 1825. Not that my motives were not as pure and as patriotic as ever carried any man into public office. Not that the calumny which was applied to the fact was not as gross and as unfounded as any that was ever propagated. Not that valued friends and highly esteemed opponents did not unite in urging my acceptance of the office. Not that the administration of Mr. Adams will not, I sincerely believe, advantageously compare with any of his predecessors, in economy, purity, prudence, and wisdom. Not that Mr. Adams was himself wanting in any of those high qualifications and upright and patriotic intentions which were suited to the office....