Proofs were not always of the same rigor - what was once considered a proof may not be so by modern standards. Now what this book shows is that 2100 years ago

Proofs were not always of the same rigor - what was once considered a proof may not be so by modern standards. Now what this book shows is that 2100 years ago some level of proof was also a requirement in Chinese mathematics; this makes classical Greek/western thought look not quite as unique as it is portrayed.