You both seem concern’d lest I have imbib’d some erroneous Opinions. Doubtless I have my Share, and when the natural Weakness and Imperfection of Human Understanding is considered, with the unavoidable Influences of Education, Custom, Books and Company, upon our Ways of thinking, I imagine a Man must have a good deal of Vanity who believes, and a good deal of Boldness who affirms, that all the Doctrines he holds, are true; and all he rejects, are false. And perhaps the same may be justly said of every Sect, Church and Society of men when they assume to themselves that Infallibility which they deny to the Popes and Councils. I think Opinions should be judg’d of by their Influences and Effects; and if a Man holds none that tend to make him less Virtuous or more vicious, it may be concluded he holds none that are dangerous; which I hope is the Case with me.

Benjamin Franklin (1706-1790) American statesman, scientist, philosopher, aphorist

Letter to Josiah and Abiah Franklin (13 Apr 1738)
    (Source)

His parents.