Dr. Jekyll and Dr. Lanyon were once friends, but this is no longer the case during the course of the novel. The reason this is so is because Lanyon does not approve of Jekyll's scientific endeavors. He feels Jekyll is probing into a dark, even perverse, territory that goes beyond mere natural science. Jekyll's interest in the nature of good and evil within the individual are too metaphysical for Lanyon's tastes.

So what does this indicate about Lanyon? It shows he's pretty traditional when it comes to his idea of the purpose of science. He thinks scientific research should stick to what can be experienced through the normal senses.

So, if Lanyon represents traditional, conventional science, then his estrangement from Jekyll becomes something more than a lost friendship. His death of shock after Jekyll transforms into Hyde before his eyes also suggests that polite society cannot handle the greater implications of Jekyll's unconventional research project: that deep down, we are all capable of great evil that cannot be explained away by reason and logic.