The Baopuzi comes in two halves that are usually read separately and were meant to be read together. The inner chapters argue that transcendence is real, attainable and technical. The outer chapters discuss government, conduct and the ordinary business of a gentleman's life. Ge Hong states plainly that he wrote both, and the pairing is his central claim rather than an accident of compilation: the Daoist pursuit is the root and the Confucian one the branches.
The inner chapters are the reason the book is famous. They rank the methods available. Breathing exercises, gymnastics, dietary restriction, sexual technique and herbal drugs all extend life, but none of them confers transcendence; only the alchemical elixirs of gold and cinnabar do that, and the cinnabar that can be cycled through nine transformations is the highest. He is scathing about practitioners who master one technique and imagine it sufficient, and scathing about the popular cults that promise results for a sacrifice.
His argument for the possibility of transcendence is empirical in temper if not in method. Strange things happen in nature, he says, and a man who has never seen them will deny them on no better ground than that he has not seen them. The reasonable position is to test the recipes. That combination, a defence of the marvellous conducted in the tone of a sceptic, is what has made the Baopuzi readable for seventeen hundred years.