Which is greater—theoretical knowledge or practical experience? Which are truer, purer, more useful, more important—the things we know with our bodies or the things we ponder inside our brains? Academics and basketball coaches have been debating the question for centuries, and it's unlikely to be resolved in another 1,000-word polemic.

But perhaps we're asking the wrong question. Maybe the question is not whether theoretical knowledge is superior or inferior to the practical, but whether there can be "theoretical knowledge" at all. Does such a thing actually exist, or is it just a theory?

Three people are talking in a doctor's waiting room.

Three ways to be a husband, a wife, a parent, a neighbor. Or is there perhaps a fourth way? "This is my body, my life," says Patient #1. "Just because the guy has a diploma hanging on his wall doesn't mean that I'm going to blindly follow his instructions. I'm going to do my own research. I'm not doing or taking anything until I'm convinced that that's the best way to go..."

"Let's face it," counters Patient #2. "It may be my body, but right now, the guy behind that door knows more about it than I do... I'm going to educate myself about my illness, but that will take time. Until I acquire that knowledge, I'm best off following the doctor's instructions."

"The guy behind that door spent eight years studying to be a doctor," opines Patient #3, "and another twenty-five years treating people in our condition. You think I'll ever acquire that kind of knowledge googling the internet? I'd just be wasting my time. I'm going to follow the doctor's instructions and leave the thinking to him... That's his job!"

Three ways to be a patient. Three ways to be a husband, a wife, a parent, a neighbor. Three ways to be a shoemaker, a teacher, an artist, a CEO. Do I defer to those who know better? Do I try to figure it out on my own? Or do I adopt a two-step approach, beginning by following those with superior knowledge and expertise until my own knowledge and expertise take over?

Three ways to live a life. Or is there perhaps a fourth way?

Patient #4 speaks up: "Patient #3 is right — no matter how much I research and educate myself, the doctor will still know more than me. So I'm going to listen to him, certainly now when I know next to nothing, and also later, after I've learned all that I can..."

"But if you're going to follow the doctor's instructions anyway," Patient #3 interjects, "why bother to study and learn? What's the point?"

"Because, like Patient #1 says, it's my body and my life. I want, I need to understand what I'm doing and why I'm doing it..."

"So it's just to make you feel better about the fact that you're submitting to a higher authority?" challenges Patient #1.

It's my body and my life. I want, I need to understand what I'm doing and why I'm doing it..." "It's not just that. The doctor needs me as an active partner in my cure. He needs me to be asking the right questions, raising the right objections, even offering my own ideas; he needs me to be reporting to him how my body is reacting to the treatment, what hurts and what feels better—none of which I could properly do if I did not understand, as best as I could, the how and why of what he's telling me to do. If my mind isn't also involved—if I'm just a passive body carrying out instructions—any cure the doctor prescribes will be of limited effectiveness..."

Wearing the arm & head tefillin
Wearing the arm & head tefillin

The tefillin are a pair of leather boxes, one worn on the arm opposite the heart, and the second worn on the head above the hairline aligned with the space between the eyes. Inside the boxes are parchment scrolls inscribed with four Torah sections (Exodus 13:1-10; Exodus 13:11-16; Deuteronomy 6:4-9; Deuteronomy 11:13-21) containing the fundamentals of the Jewish faith.

The arm and the head are the two basic instruments of life: action and knowledge. The tefillin represent the "binding" and dedication of these instruments of life to serve G‑d.

Numerous laws govern the making of the tefillin and the manner in which they are worn. The Chassidic masters teach that each Torah law has both a body and a soul — a practical instruction and an inner significance. So the laws of tefillin can be understood on two levels: as a set of instructions on how to make and wear tefillin; and as a thesis on the nature of mind and deed, their relationship to each other and the manner in which they serve our mission in life.

One of the laws of tefillin concerns the order in which they are put on and removed: first we bind the tefillin on the arm, then we place the tefillin on the head. In removing the tefillin, the order is reversed: first the head-tefillin are removed, and then the arm-tefillin. This law is derived from the verse, "and they shall be as tefillin between your eyes."1 Emphasizing the plural form of the word vehayu--"and they shall be"--the Talmud understands the verse to imply, "at any time that there is tefillin between your eyes, there shall be both."2

In other words, there may be times and situations in which you're wearing only the arm-tefillin--i.e., before you put on the head-tefillin or after you removed it —but never a time or situation in which the head-tefillin are being worn without the arm-tefillin.

What does this tell us about the "head" and the "arm"? Many things, but let us note four basic truths about the interplay between mind and action:

1) We need both. We cannot say, "I trust G‑d. I'll follow His commands. I don't need to understand." Nor can we say, "The important thing is to understand what G‑d is telling us with all these commandments about Himself, about life in general. Actually doing them—well, if it does something for you, fine, but that's not what it's about." Our relationship with G‑d should encompass our entire being—mind as well as deed, action as well as thought. That's why there are two tefillin--one for the arm and one for the head.

2) Doing comes first. The basis and foundation of our lives are the mitzvot—the divine commandments. Saying, "I won't do it until I fully understand" is like refusing to take the medicine the doctor has prescribed until you understand exactly how antibiotics are made and how they neutralize bacteria, or refusing to breathe until you've studied how the lungs function and why your body requires oxygen... That's why the arm-tefillin are put on first, before the head-tefillin.

Saying, "I won't do it until I fully understand" is like refusing to take medicine until you understand exactly how antibiotics work. 3) Commitment and deed transcend understanding. Even after we've studied and understood, to the full extent that we are able, there will still be times and situations when we don't fully understand and need to simply obey and trust the wisdom of our Creator. We need to be able to say to ourselves, "This is what I understand, and it has made my doing that much more meaningful. But there's more to life than what I can understand. If I stop here, I'm cutting myself out from the infinite truth that lies beyond the humanly knowable truth." This is implied by the law that the head-tefillin are removed first, indicating that will be times when the arm-tefillin remain on their own after the head-tefillin have been applied.

4) There cannot be knowledge without action. This is expressed by the axiom, "At any time that there is tefillin between your eyes, there shall be both." While it may be the case that we are enwrapped in the arm-tefillin without the head-tefillin (either because we haven't yet attained full understanding, or because we've advanced beyond it) the reverse is never the case. In other words, there's no such thing as "theoretical knowledge." Thought that is uncoupled from action understands nothing at all.

Knowledge adds depth to our doing. Doing is what makes our knowledge know.