Can the often volatile pattern of behavior (“Sinning against health as long as health is good; sacrificing everything for health when health is bad”) be brought into line with rationality? Or are...

Can the often volatile pattern of behavior (“Sinning against health as long as health is good; sacrificing everything for health when health is bad”) be brought into line with rationality? Or are individual preferences inconsistent, implying that medical experts should perhaps determine the appropriate amount of preventive behaviors?