I was doing my regular workout the other day, the kind of karate practice I’ve been doing since my twenties, when, in the middle of a form I was working through, a fly whizzed by my head. I’m no fan of flies, at least in the house, because of the diseases they transport as they light on different surfaces, so I stopped what I was doing and followed his trail. I caught up with him as he came to rest on the window of our back door and took a couple of quick swipes at him. The sun was coming in through the window so he probably didn't "know" I was behind him. Still, he was fast and it took me three tries to bring him down. And on the third shot, I wasn't even sure I'd got him till I found him, still alive, crawling on the floor at my feet. He was still fast and I had to move quickly to catch him and then press hard enough to crush him. Insects are pretty tough and can withstand a lot of pressure from the human finger or hand. But I got him in the end and, after placing his carcass in the garbage and washing my hands, I went back to my workout.

But almost as soon as I'd begun the next form (after restarting and finishing the one I'd interrupted), I was disconcerted to see another fly, just like the first, buzzing about. I tried to push myself to finish the form I was into until I saw the little bugger light on another window, near where I was practicing, and so I stopped again and carefully approached him. I don't know if this one was quicker than the first or the light wasn't in my favor in that part of the house but he got away.

Still, he was drawn to the light and the sun shining through the window seemed to keep calling him back. I started and stopped the form I’d been concentrating on several times, cutting it short each time that second fly landed on the window shades and then, each time, I’d approach it as stealthily as I could. But this one was quick and the light was probably not in my favor. But something else noticeable was happening. This one seemed to be learning.

Now flies don't have much in the way of brains and we humans are pretty sure that the brain matters when it comes to smarts. Yet this tiny creature, whose brain was orders of magnitude smaller than mine, with far fewer cells and less complexity in its structure, seemed to not only be becoming increasingly aware of my presence, he actually seemed to anticipate me. That's something we usually associate with intelligence.

The last time I thought I had him cornered I got really close, close enough to see him rubbing his legs together as he rested on the window shade and then, as I approached (my guess is he caught sight of a big shadow moving on him) he stopped rubbing his legs and seemed to ready himself, waiting. When I struck again, he was gone in a flash. He had not only reacted with the sort of fly-reflex his kind possesses to steer clear of bigger monsters like me, he was waiting and seemed to be gauging his moment. Of course, I missed again. But this guy seemed to have learned something from our several brief encounters. He refused to alight again, flying about, sometimes right past my head but not going near the windows and certainly not landing. And mostly giving me a wide berth. He was clearly agitated by something. My presence? Had he learned, with his tiny insect brain?

Certainly there is no evidence he thought about his situation as a human might but he did seem to be anticipating me and he did seem to have learned where danger lay for him. Now perhaps this is just anthropomorphocizing on my part. I certainly don't want to impute anything like human consciousness to my miniscule antagonist, but it hit me that there was something going on here that did not look entirely like mere stimulus-response. There was an entity before me in a situation and responding to it, to the threat it posed. Surely that fly had no idea about what a human was or why the human was trying to kill it and, probably, it had no idea that it was facing its death at all. But it knew something and it learned something and learning is the first measure of intelligence. Thermostats can respond to signals from their environment but do not learn anything about them. But that little fly learned.

So, what is intelligence? We humans often think of it as being able to recognize changes and plan our actions accordingly. We have language so we talk to ourselves, too, tell ourselves stories about what’s going on. We can conceptualize our situations. At a deeper level, especially in the martial arts, humans train themselves in ways that recall the fly’s behavior. The practice of martial arts or any activity in sport or real life involves conditioning our bodies through the awareness having a body involves. In the martial arts, like the karate I practice, we train to be one with the environment of combat. The point is not to plan our actions ahead of time or to try to plan our next response to whatever attack is coming our way, but to teach ourselves to allow our bodies to feel and respond to the danger. In a real combat situation, there's no time to take stock of the strike or kick or tackle that's coming at you. It just happens and if you've trained well enough, so does your response. Years ago, confronted by an armed assailant in a darkened schoolyard playground at night without any lights, a place I had foolishly decided to cross (it was a shortcut home!) despite seeing two men sitting in the shadows there with both looking at me and talking quietly at sight of me and then rising, as I entered the area, and walking deliberately towards me, I had faced the sort of danger the fly was facing. Like that first fly, and maybe even the second, I was insufficiently aware of the danger as I entered the schoolyard though I had plenty of information to enable me to have anticipated it. But I was still processing the situation when one of the men ran toward me, a gun in his hand, shoving it in my face as he demanded my money.

Like the fly, my body responded, though my mind, the thinking part anyway, was still trying to parse my predicament. As the gun entered my space, I knocked it from my assailant's hand. Just as the fly had sped away as I reached towards it, so my hand removed the immediate threat of the weapon to my person. My assailant was nonplussed and what happened after is another story but the relevant part here is that my body, having trained for some eight years by then in the martial arts, had developed a kind of intelligence all its own. It knew, though my thinking brain did not quite get it yet, that there was, as the robot puts it in the series Lost in Space, "Danger, Will Robinson" and I was Will Robinson. Martial arts training at its best aims to teach the body to do what the thinking brain cannot. It aims to make the body smart in the way creatures in the wild are smart . . . and in the way that fly in my house was.

But how explain the fly's ability to learn so quickly, to seemingly anticipate and then avoid putting itself in danger again? Reflex attuned by eons of evolutionary development perhaps, the sort of thing all creatures possess though humans have to train themselves to bring back to the surface? But what then is intelligence? Is it being able speak a language, solve a math problem, build a bridge? Is it knowing how to play chess well? Is it only a function of sufficiently large and complex brains?

Or is it something else, something deeply embedded in the universe itself, of which we are all a part? What if intelligence is built into the very fabric of the universe? What if having big brains is only one expression of it? What if evolution, itself, is intelligence? Maybe we go wrong when we think of the universe in a merely mechanical way, as if it were just a naturally occurring super-duper thermostat. Maybe the fly has intelligence because it is an expression of the universe itself and we are, as well, though, as humans, with concept forming (and using) brains, we lose sight of this deeper fact about ourselves.

Maybe intelligence runs through everything in the universe and finds expression in different ways. In us it's brains with the power of language and the conceptualizing capacity language enables. But in flies, perhaps it's something else. In the end we're all part of the same fabric of existence and who knows what part of it, or how much of it, humanity really represents . . . or how long we can hang around to compete with the fly?