談古論今

to talk of the past and discuss the present (idiom) / to chat freely / to discuss everything

now / the present time / current / contemporary / this (day, year etc)

surname Gu

ancient / old / paleo-

surname Tan

to speak / to talk / to converse / to chat / to discuss

abbr. for 論語|论语[Lun2 yu3], The Analects (of Confucius)

opinion / view / theory / doctrine / to discuss / to talk about / to regard / to consider / per / by the (kilometer, hour etc)