"An unsophisticated forecaster uses statistics as a drunken man uses lamp-posts - for support rather than for illumination"

This quote by Andrew Lang is a metaphor that compares an unsophisticated forecaster to a drunken male. The forecaster is compared to an intoxicated man who utilizes lamp-posts for assistance instead of for lighting. This indicates that the forecaster is not utilizing data to gain insight or understanding, but rather to prop up their own ideas and viewpoints. The quote recommends that the forecaster is not taking the time to appropriately evaluate the data and draw significant conclusions. Instead, they are counting on the information to support their own preconceived notions. This is a warning versus utilizing stats as a crutch rather than a tool for getting knowledge. It is necessary to use information to get insight and understanding, rather than simply to support one's own ideas.