Plato’s cave is one of the greatest philosophical fictions ever invented. The idea that we don’t truly see the real world but only the mere shadows of things, that our perception of reality is limited by our own flawed senses is such a powerful concept that it remains a topic of debate and discussion 2500 years later, just as Plato’s work, the Republic continues to be the foundation of the Western intellectual canon.

In writing about Plato, Robephiles notes that “Plato was distrustful of the senses when it came to the ability to perceive knowledge. Plato knew that our senses could be fooled and he placed an emphasis on our abilities to think and reason rather than the knowledge gained from the study of the physical world.

This leads us to another famous metaphysical idea, The Theory of the Forms. Plato was fascinated by the problems of universals. An example would be as if I told you I had a dog. If I told you this you might picture a poodle or you might picture a mastiff or a chow or a border collie. These are all dogs yet each one is so different in its particulars. What makes a dog have its essential ‘dogness’? “

In an age of data science, Monte Carlo simulations and million backtests per second, the empirical model -- so successful in the physical sciences -- now completely dominates our world of social science of which finance and trading are a part.

But what if I were to say to you that maybe we have it all wrong? What if I were to argue that the endless data mining we all do -- the search for the perfect indicator, the perfect Fib level, the perfect volatility envelope are all just a giant waste of time. Ironically enough, empiricism would prove me right. Almost every trading system ever invented fails miserably under real-life conditions despite often showing perfect statistical accuracy often to the 99% confidence level. The irony of trading is that we put all our faith in an empirical model that empirically fail us.

But what if we set aside all of our modern tools of computation and started thinking like a 2500-year-old philosopher? What if we applied Plato’s Theory of Forms to the very pedestrian idea of a trend? Granted, trend can come in many shapes and sizes. It could be jagged and rambling with massive choppiness within it. It could be steady and smooth with hardly a retrace in the move. Or it could be something in between.

However, the “trendiness” of trend just like the essential “dogness” of dog is marked by some general characteristics that make it identifiable. In case of trend the best “class” of trend is one marked by higher highs in an uptrend and lower lows in a downtrend.

Thinking about this “Platonic ideal of trend” has really helped me refine my latest trading system. It made me eliminate any element that is extraneous to the setup -- and because it forced me to create much stricter rules for entry, I make much fewer trades. On the face of it that may sound like a negative to a daytrader like me, but in reality, it made my trades much more accurate than before. And it gave me clarity of analysis that I’ve rarely had before.

In the modern world, so full of experimentation and empiricism, we are conditioned to stay away from deductive reasoning. But perhaps the truth is just the opposite. Perhaps instead of running endless backtests to torture the price data, we should just imagine the ideal version of our setup. Perhaps in trading what we need is a lot less data science and a lot more Platonic philosophy.