If you drag your shoe a bit those plastic spikes or rubber spikes can be almost as bad as metal spikes.
“For if enough people were really convinced that growth should be halted, and if they acted on that conviction, then billions of others might be deprived of any realistic hope of gaining the opportunities now enjoyed by the more fortunate.”
“It is incumbent on every generation to pay its own debts as it goes. A principle which if acted on would save one-half the wars of the world.”