Inane, perhaps. I don't think these ideas can be separated from their time and place. Like most philosophical/intellectual movements, a lot of what they are is

Inane, perhaps. I don't think these ideas can be separated from their time and place. Like most philosophical/intellectual movements, a lot of what they are is objections, dialogue and alternatives to previous ideas or competing ideas. To us, 2-300 years later, we don't necessarily need a concrete basis for secular morality. We also don't expect morality to be reducible to a simle principle like F=ma. To them, they were in a period where medieval theology was being replaced by secular philosophy and science. They expected morality to be solved like Newton and Galileo had solved problems in their domains. We don't expect this anymore.