Much of life in the 21st Century is unlike that of any other age in the history of the world. As one example, the daily work of past eras required almost endless activity and manual labor, while today’s average worker is asked to do precisely the opposite. It’s a simple reality that a majority of us now sit for hours on end each day to the detriment of our health.

A sedentary lifestyle – especially when combined with other widespread issues like the rampant addiction to screens – can easily contribute to a whole host of problems, the most apparent and significant of which are depression, anxiety, shorter attention span, and diminished cognitive ability in general

These are jarring and increasingly widespread issues facing our culture, no matter a person’s religious belief, and even more unsettling is that our world doesn’t appear to be reversing course anytime soon. 

To the Christian, these should be all the more terrifying because of their effects on both the body and the soul. After all, we believe in the Incarnation, that Jesus Christ became man and dwelt among us. Jesus was “like us in all things but sin,” as we read in Hebrews – which means that He, like us, possessed both a mind and a body, and used both to the fullest of their abilities to accomplish the mission that the Father had laid before Him.  

The health of our bodies is hardly mentioned when talk of holiness comes up, however. Sure, incarnational acts like kneeling, praying a Rosary, or receiving the Eucharist are commonly emphasized as key components of a solidly Christian life, but the idea that one must be equally attentive to their physical well being as to their spiritual well being, in order to more fully find holiness, seems oddly foreign.

And yet, such a belief is well-established in our Catholic tradition. It was none other than St. Thomas Aquinas who wrote: 

“To a good bodily constitution corresponds the nobility of the soul.”

This quote appeared in the 1921 book The Intellectual Life, by Fr. A.G. Sertillanges, OP. The book itself is written primarily for those wishing to pursue a life of study, but many parts apply widely to the average Christian – in particular the section on how caring for the body is necessary for a life of holiness. 

Sertillanges, after acknowledging that this idea “customarily startles spiritual persons who lack firmness of judgement” (ouch), begins by exhorting the reader:

“Do not be ashamed to endeavor to keep well. Some men of genius have had miserably bad health, and if it is God’s will that that should happen to you, there is no more to be said. But if [bad health] is your own fault, it is a very guilty instance of tempting God.”

He of course acknowledges that anyone who is prone to bad health, through no fault of their own, will have a different and more noble route to holiness. Such is the beauty of redemptive suffering. 

However, Sertillanges’ caveat likely only applies to a minority of persons, which means that the rest of us have a duty to keep our bodies in good condition, that we might more readily be able to hear the promptings of the Lord in our lives.

Sertillanges’ advice that followed – boiled down here to 5 keys seemingly unrelated to the spiritual life – is bound to help in the pursuit of a holy life: 

1. “Sound hygiene is almost an intellectual virtue. Among our moderns, whose philosophy is sometimes so poor, the science of hygiene is rich; do not despise it; it will enrich your philosophy.”

A novel idea! Shower. Brush your teeth. Change your underwear. It’s almost like our moms were onto something – good hygiene will not only be appreciated by those around you, but a refreshed body will undoubtedly lead to a refreshed mind, better able to hear the voice of God. 

2. “Live as much as possible in the open air. It is a recognized fact that attention … is closely related to breathing, and for general health we know that plenty of oxygen is a first condition. Windows open or partly open day and night when prudence allows, frequent deep breathing exercises, combined with movements that amplify them and make them normal, walks before and after work or even combined with work according to the Greek tradition; all these practices are excellent.”

When so many of us now live in concrete jungles, or are cooped up inside at a desk for a large part of each day, getting up, walking around, and breathing in fresh air has become almost a luxury. Nevertheless, it’s a luxury worth squeezing in – and it’s beginning to be backed up by ample research, to boot. 

3. “Look after your diet. Light food, plain, moderate in quantity and simply cooked, will enable you to work more freely and alertly. A thinker does not spend his life in the processes of digestion.”

Ask anyone who’s walked into a chapel right after eating half a pizza at a Youth Group night, and you’ll know that an overly full belly doesn’t exactly allow for a positive prayer experience. There’s a reason why fasting is such a huge thing in the Catholic tradition – hunger for food naturally corresponds to a hunger for God, properly disposed. Of course, food is a creation of God, and is also “very good” – but gluttony remains one of the Seven Deadly Sins. 

4. “Every day you should take exercise. Remember the saying of an English doctor: ‘Those who do not find time to take exercise must find time to be ill.’”

Mic drop. Such a pithy, truth-filled line really puts that $50-a-month gym membership into perspective. Which would you rather do – suffer a little now by going for a jog? Or suffer a lot later by reaping the consequences of decades of no exercise? And as if we even needed the proof, what Sertillanges intuited almost 100 years ago is now being convincingly borne out in recent studies.

5. “Pay still more attention to your sleep. Take neither too much nor too little. Too much will make you heavy, stupid, will slow up the blood and the power of thinking; too little will expose you to the risk of prolonging unduly the stimulation of work and dangerously superimposing strain upon strain.”

This one almost goes without saying. Anyone who’s had a 20-minute power nap stretch into a 3-hour snoozefest knows firsthand that feeling of being “heavy” and “stupid” in the hour after waking up. As with anything else in life, a proper equilibrium is needed with one’s sleep pattern in order to make the most of our Christian life. 

In all things, Sertillanges begs the reader to be intentional with the way one’s life is lived, to love God above all else, so as to be truly free to exercise our will in service to something greater. He concludes his bit on good bodily health by saying: 

If one remains lazy, a glutton, a slave of the pillow and of the table; if one abuses wine, alcohol, tobacco; if one forgets oneself among unwholesome excitements, clinging to habits that are both debilitating and nerve-exhausting, to sins that are perhaps periodically forgiven, but of which the effects remain, how can one practice the hygiene of which we have urged necessity?

A lover of pleasure is an enemy of his body and therefore quickly becomes an enemy of his soul. I say to you … that discipline and mortification of the body, along with the necessary care of it … are among the most precious safeguards of your future.

May we all have the courage to rise above our temptations, and follow the path the Lord has laid out for us. St. Thomas Aquinas, pray for us!