No man should be a perfect physician to any but himself. - Luigi Cornaro

A man can enjoy a terrestrial paradise after eighty, but it is not to be obtained, except by strict temperance in food and drink, virtues acceptable to God, and friends to reason.

It follows then that it is impossible to be a perfect doctor for another person. A person can’t have a better guide than himself or any prescription better than the regular living that I’ve described. I don’t mean to say that those who live this regular life don’t ever need a doctor or that we shouldn’t give him the respect he’s due. We should call a doctor when we get sick. But for simply staying healthy, it’s my opinion that we should consider this self-controlled, regular life as our doctor, since it keeps even weak people healthy and causes them to live well and hearty to the age of one-hundred and further.

It is universally agreed, that custom, in time, becomes a second nature, forcing men to use that, whether good or bad, to which they have been habituated; in fact, we see habit, in many instances, gain the ascendency over reason. This is so undeniably true, that, virtuous men, by keeping company with wicked, often fall into the same vicious course of life. Seeing and considering all this, I have decided to write on the vice of intemperance, in eating and drinking. Now, though all are agreed, that intemperance is the parent of gluttony, and sober living the offspring of abstemiousness, yet, owing to the power of custom, the former is considered a virtue, and the latter as mean and avaricious, and so many men are blinded and besotted to such a degree, that they come to the age of forty or fifty, burdened with strange and painful infirmities, which render them decrepit and useless, whereas, had they lived temperately and soberly, they would in all probability, have been sound and hearty, to the age of eighty and upwards.