There are two kinds of disease of the soul, vice and ignorance.

The soul, like the body, accepts by practice whatever habit one wishes it to contact.

I only know that I know nothing

By all implies marry if you get a great wife/husband, you are going to be pleased. If you get a bad a single, you are going to become a philosopher.

Be of good cheer about death and know this as a truth, that no evil can happen to a good man, either in life or after death

It is a base thing for a man to wax old in careless self-neglect before he has lifted up his eyes and seen what manner of man he was made to be, in the full perfection of bodily strength and beauty. But these glories are withheld from him who is guilty of self-neglect, for they are not wont to blaze forth unbidden.

If all misfortunes were laid in one common heap whence everyone must take an equal portion, most people would be contented to take their own and depart.