Don't think the solid and spiritual parts of you are the same as when you were born. Everything you are now — your body and life — came from food you ate and air you breathed just two or three days ago. You are like a river that stays the same only because new water keeps flowing through it. What you have received recently, not what came from your mother, is what changes and breaks down. But even if the solid parts of your body stayed with you forever, what does that matter? The real qualities that make you who you are — those are completely different.
Now that solid and spiritual that we speak of, thou must not conceive it to be that very same, which at first was, when thou wert born. For alas! all this that now thou art in either kind, either for matter of substance, or of life, hath but two or three days ago partly from meats eaten, and partly from air breathed in, received all its influx, being the same then in no other respect, than a running river, maintained by the perpetual influx and new supply of waters, is the same. That therefore which thou hast since received, not that which came from thy mother, is that which comes to change and corruption. But suppose that that for the general substance, and more solid part of it, should still cleave unto thee never so close, yet what is that to the proper qualities and affections of it, by which persons are distinguished, which certainly are quite different?