We should all try to keep a healthy body in a healthy mind. Keeping the body heathy is fairly simple at least in principle. We just need to do sufficient exercise and eat the right food. I do a little bit of cycling, walking and swimming – just enough to prevent myself from becoming unfit. We can’t ward off the ravages of age or unexpected afflictions but we do have some control over our bodies.
Keeping the mind fit is more problematic. Claims that mind-exercises or Sudoko or crosswords keep the mind alert have now been debunked. Doing them may make you better at mind-exercises, Sudoko or crosswords but not at any other mental activity. This is where for me Ancient Greek comes in. I have set myself the task of reading a certain amount of Greek every day – currently at least a hundred lines of Homer. The point here is that I am exercising my mind in two ways. The first is the actual mental act of translating and the second is the understanding of what I have translated. One exercises the mental processes and the other introduces me to new ideas. There are myriad of other ways of keeping mind and body fit but these are mine.
This is what Plato had to say about the relationship of the mind and the body.
πρὸς γὰρ ὑγιείας καὶ νόσους ἀρετάς τε καὶ κακίας οὐδεμία συμμετρία καὶ ἀμετρία μείζων ἢ ψυχῆς αὐτῆς πρὸς σῶμα αὐτό: ὧν οὐδὲν σκοποῦμεν οὐδ᾽ ἐννοοῦμεν, ὅτι ψυχὴν ἰσχυρὰν καὶ πάντῃ μεγάλην ἀσθενέστερον καὶ ἔλαττον εἶδος ὅταν ὀχῇ, καὶ ὅταν αὖ τοὐναντίον συμπαγῆτον τούτω, οὐ καλὸν ὅλον τὸ ζῷον—ἀσύμμετρον γὰρ ταῖς μεγίσταις συμμετρίαις—τὸ δὲ ἐναντίως ἔχον πάντων θεαμάτων τῷ δυναμένῳ καθορᾶν κάλλιστον καὶ ἐρασμιώτατον.
When we look at health and disease in the body and virtue and vice in the soul, there is no more important proportion (or lack of it) than that of the soul to the body. We don’t think of this or keep it in our minds that when a weaker body contains a strong and great soul, or the opposite, the whole creature is not in a good state. Because it lacks proportion where proportion is most important. But where the proportion is right, it is the best and most lovely sight to see.
Plato Timaeus 87d