Educate men without religion and you make of them but clever devils.

The saying warns that intellectual training alone is morally insufficient: sharpened minds, if not guided by a religious (or at least ethical) framework, may become more capable of wrongdoing. “Clever devils” implies that education can amplify a person’s power—rhetorical, technical, administrative—without necessarily improving character. The underlying claim is that religion supplies restraint, conscience, and a sense of accountability beyond human law, and that removing it from education risks producing skilled but unscrupulous actors. In modern terms, it anticipates debates about values education: whether schools should cultivate virtue alongside knowledge, and what foundations (religious or secular) can reliably do so.