Scientifically, how much did the ancient Greeks get right?

I’ve read a bit about the history of Western science, and it’s generally taken for granted that it started with ancient Greek science.

But (for instance) Aristotle seems to have got just about everything wrong. He believed that the Sun went round the Earth; that heavy objects fell faster than light ones; that there were only four elements; and so on. This would have been bad enough by itself, but since the Church in the middle ages regarded Aristotle as the authoritative answer to any question not answered in the Bible, it wasn’t until modern times that all this was put right.

Did the ancient Greek philosophers actually achieve anything in science other than setting everyone on the wrong track? If so, what did they actually get right?

Can we expand the term ‘science’ to encompass mathmatics and engineering? If so I can give you some examples of Greek ‘science’ that is still relevent today…and a bunch of examples of engineering where they ‘got it right’ far ahead of their time…in fact, some things that weren’t re-discovered for centuries or longer.

-XT

Peter Watson made an excellent point in his excellent book, Ideas: A History of Thought and Invention from Fire to Freud (seriously, it’s spectacular and you should pick it up). He wrote that “to be influential, an idea does not have to be right.” Sigmund Freud, the dominant intellectual presence of our century was, for the most part, wrong.

Science is progressive, a series of steps that get closer and closer to the truth but never really get there. We are probably incorrect on virtually everything too - the important thing is, though, that we are more correct than Aristotle. Physics is an excellent example of this - Newton has been quite thoroughly proven incorrect, and Einstein has been brought into question as well. Aristotle is no different - I’d be immensely surprised if he got anything 100% right, just as I’d be immensely surprised if modern science has got anything 100% right.

No. Mathematics is not science. It’s a fine thing in itself, and science depends upon it, but it’s not science as I understand it. Engineering… well maybe. Give me a concrete example and I might accept it.

Didn’t the classic greeks figure that the earth was round and calculate the size of it pretty accurately?

Eratosthenes used maths (and observation) to estimate the size of the Earth and got it surprisingly close. Is this the sort of thing you want?

Well, if math is out (I don’t see why, but its your OP :)), how about this for engineering:

There are a lot of other examples of Greek engineering…and of course, there are several scientific principals from ole Archimedes himself.

-XT

Indeed, Eratosthenes believed that all the earth’s oceans were connected, that Africa could be circumnavigated, and that India could be reached by sailing westward from Spain. He calculated the correct duration of a year and calculated the diameter of the Earth to within fifty miles using a bowl, a vertical rod, and calculations based on the different shadows at different locations at the same time of day.
His fellow scholars referred to him sometimes as “Beta.” Plato was Alpha.

Hipparchus later amended Eratosthenes’s calculations to come even closer, but Ptolemy later did the calculations on his own and seriously underestimated the size of the earth. His calculations indicated that the earth was about 70% smaller than it is in reality. Columbus, in fact, was not odd for believing that the Earth was round, but for believing Ptolemy was correct while almost everyone else believe Eratosthenes’s numbers. As a result, Columbus believed he could store enough supplies to sail to India because he thought the Earth was small enough, while others disagreed.

There were a lot of amazing discoveries in ancient Greece that tend to get forgotten. Herophilus, for instance, made the first scientific examinations of the minutiae of the human body, detailing nerve structure, demystifying the womb, and explaining the rough structure of the brain. On the other hand, he also thought that people’s heart rates changed according to different metric systems as they got older. Infants had pyrrhic pulses, young adults had trochaic pulses, the elderly had iambic pulses… he was a bit off in that field.

The Greeks weren’t really experimenters, in the way we think of scientists today. They were thinkers, or more accurately, philosophers, I guess. You can’t really do science, as we know it, without the scientific method, and that wasn’t “invented” until the 17th or 18th centuries in Europe. It’s not surprising that they didn’t get much science right, although they certain could get lots of things done from an engineering standpoint.

One of the best examples of Greek science is that they knew the earth was round, and they had a pretty good measure of its diameter, although they were probably off by about 15% (we don’t know the precise length of the unit of measure used, the stadion).

Aristotle specifically is remembered more for laying the groundwork for science than for coming up with scientific ideas. He was, to Bertrand Russell, “The first to write like a professor… a professional teacher, not an inspired prophet.” While Plato and earlier Greek thinkers thought that intuition was just as valid as empiricism and logic, Aristotle focused on research. His analysis of political systems included a documentation of 158 different systems across the Mediterranean world, for instance, and he derived his conclusions (that governments differ based on climate, historical precedents, and geographical conditions and that an ideal city is impossible) from his observations.
He was an extraordinarily strong believer in logic - too strong, perhaps, and his belief that “nature does nothing in vain” could be problematic when he stretched to find reasons for all sorts of things.

Well, OK… but I’ve heard that the accuracy of this calculation depends on the size of Eratosthenes’ measuring units. He measured the circumference of the Earth in “stadia” but no-one’s sure how long a “stadium” was. By one definition he was only 0.5 percent out, but by another he was 17 percent wrong.

Edit: I see that John Mace has already made this point.

  • The shape of the earth and its approximate size, as noted above.

  • The physical causes of eclipses.

  • The order of the sun and moon and the five naked-eye-visible planets, in terms of distance from the earth.

  • The spherical shape of the sun and moon.

  • Spherical astronomy in general, so that the positions of celestial bodies could be predicted trigonometrically. (Although the geocentric hypothesis and circular planetary orbits weren’t “right”, the basic spherical astronomy built on them is still used as a conceptually simple approximate model for observers and navigators.)

  • Timekeeping with instruments like sundials and astrolabes, designed using the geometry and trigonometry of spherical astronomy.

  • Basic geometric optics, including the properties of curved mirrors and quantitative models of reflection and refraction.

  • Basic quantitative mechanics of simple machines like pulleys and levers, as well as hydrostatics.

  • Anatomy of the brain and nervous system as well as other organs, the muscle and skeletal systems, etc.

Those are just the ones I can think of off the top of my head, and there are lots of others.

Short answer: the Hellenistic Greeks (with some input from other cultures’ intellectual traditions, btw) did get a lot of basic science right. And in many cases, pace John Mace, they got their results using rational processes essentially indistinguishable from the modern scientific method. The only real difference between their scientific method and ours is that they had less rigorous requirements about when it needed to be applied, and what kinds of other “scientific” techniques were considered acceptable alongside it.

I don’t know, they seemed like pretty huge differences. Plato, for instance, believed that Knowledge existed in four states only - illusion, belief, mathematical knowledge, and dialectic (discussion and criticism). He looked down on the techniques of observation and empiricism essential to modern science, and elevated mystical intuitionism. He was hardly alone in these views. Many Greeks believed that having a hunch that something was true was just as valid as proving it logically.

He also may have simply gotten lucky, and had his errors cancel. He assumed that Alexandria was due north of Syene (modern day Aswan) - in fact, it’s a few degrees west. Nor was the sun precisely overhead on the day of the solstice in Syene, which is actually somewhat north of the Tropic of Cancer. His estimate of the distance between the two places came from caravan drivers, and probably wasn’t terrifically accurate. Nor did he have extremely precise instruments to measure the angle of the sun in Alexandria at noon on the solstice. His theory was sound, but he simply couldn’t have had good enough data to reliably get the answer spot on.

How about concrete? Is that concrete enough? :slight_smile:

So do many people in modern societies today. The question is, what do the practicing scientists think? Plato was not a scientist, and his views on the validity of different kinds of knowledge had some significant divergences from those espoused in many cases by people like Archimedes, Hipparchus, Galen, and Ptolemy.

Again, I’m not arguing that the Hellenistic Greeks approached science in exactly the same way that modern scientists do. But many of the quantitative explanations that they devised for observed phenomena were modeled and tested using rational processes that weren’t significantly different from what we now call “the scientific method”.

There is a certain amount of intuitiveness or “common sense” about the scientific method, so it’s not surprising that they did use similar rational processes at times.

However, the Greeks tended to simply reason their way, deductively, to “scientific truth” as opposed to the more inductive process used by modern scientists. Wikipedia has a pretty good article on the History of the Scientific Method which discusses this.

I almost posted that, but wasn’t it the Romans who invented concrete (or at least what we would recognize as concrete)?

I might be wrong here (almost a certainty :)), but wasn’t this a Roman invention?

-XT

I realize there is some debate here as to whether pure math should be included, but Greek mathemeticians did manage to work out some fiendishly difficult theorems; all the more remarkable when modern algebraic notation did not exist.