A quotation in the second volume of Rothbard's "Conceived in Liberty" sent me digging for the source, which comes from a rich vein indeed: Cato's Letters, by John Trenchard and Thomas Gordon. Yet again, I must express my gratitude to Liberty Fund for making these works available online and in print. Below are only two extracts from the essay (by Gordon). The whole thing can be found via the link.
An Enquiry into the Nature and Extent of Liberty; with its Loveliness and Advantages, and the vile Effects of Slavery.
"Let people alone, and they will take care of themselves, and do it best; and if they do not, a sufficient punishment will follow their neglect, without the magistrate's interposition and penalties. It is plain, that such busy care and officious intrusion into the personal affairs, or private actions, thoughts, and imaginations of men, has in it more craft than kindness; and is only a device to mislead people, and pick their pockets, under the false pretence of the publick and their private good. To quarrel with any man for his opinions, humours, or the fashion of his clothes, is an offence taken without being given. What is it to a magistrate how I wash my hands, or cut my corns; what fashion or colours I wear, or what notions I entertain, or what gestures I use, or what words I pronounce, when they please me, and do him and my neighbour no hurt? As well may he determine the colour of my hair, and control my shape and features.
True and impartial liberty is therefore the right of every man to pursue the natural, reasonable, and religious dictates of his own mind; to think what he will, and act as he thinks, provided he acts not to the prejudice of another; to spend his own money himself, and lay out the produce of his labour his own way; and to labour for his own pleasure and profit, and not for others who are idle, and would live and riot by pillaging and oppressing him, and those that are like him."