Domestic education is the institution of nature; public education, the contrivance of man.
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

Context

“and respect for them may frequently impose no useless restraint upon your own. Surely no acquirement, which can possibly be derived from what is called a public education, can make any sort of compensation for what is almost certainly and necessarily lost by it. Domestic education is the institution of nature; public education, the contrivance of man. It is surely unnecessary to say, which is likely to be the wisest. In some tragedies and romances, we meet with many beautiful and interesting scenes, founded upon, what is called, the force of blood, or upon the wonderful affection which near relations are supposed to conceive for one another, even before they know that they have any such connection.” source