Archive for August, 2011

In discussing Roger Bacon, I casually mentioned that he was the contemporary of Robert Grosseteste, as if that were a name everyone should recognize. Maybe it is, but in case you don’t, here’s the scoop.

Grosseteste lived from 1175 to 1253, entirely overlapping the life of St. Francis, whose Friars he taught at Oxford; remember, Roger Bacon was a Franciscan; he may or may not have actually met Grosseteste. He was also Bishop of Lincoln for the last 20 years of his life.

What else?

Well, it is interesting to note and he wrote an allegory about redemption called the Castle of Love. In his story, a king has four daughters, mercy, justice, truth, and peace, and they argue about the rightful fate of a guilty vassal. It’s an interesting approach to the doctrine of the atonement, and the fact that he wrote it is a measure of his desire to preach the gospel persuasively.

He was a good bishop.

He was a good statesman, which was part of the job of being a bishop in those days.

He was also an important philosopher, one who influenced Roger Bacon. Between 1230 and 1235, he wrote commentaries on Aristotle for his students, and one important aspect of this is that he certainly understood the dual path of scientific reasoning:

  1. One generalizes from observations and comes to a conclusion about universal principles.
  2. From that universal conclusion, one lays out what to expect in terms of observation and then checks whether new observations further affirm the universal principle or require its correction.

In other words, science requires both inductive reasoning, which goes from many observations to a single principle, and deductive reasoning, which goes from an abstract principle to the interpretation of many individual facts. He called inductive reasoning “resolution” since it brings many things into focus; he called deductive reasoning “composition” because it suggests how to place other physical events under the umbrella of a principle. Science consists of resolution and composition.

Seems obvious, but lesser men emphasize one path at the expense of the other. His ideas formed a tradition of placing science firmly in the realm of observation and experimental verification, and Galileo specifically built upon that tradition almost 400 years later.

Geometry and Optics

It is really impossible to think of studying optics without a knowledge of geometry. What is reflection if not geometry? Light strikes a flat surface, and the angle at which it falls is the same as the angle at which it bounces away: “the angle of incidence is equal to the angle of reflection.” Grosseteste wrote about optics and about the importance of math for good science.

He also wrote thoughtfully about the rainbow, although I don’t know exactly what he said because what I found about this quickly turned to a discussion of Roger Bacon’s development of his ideas. Nevertheless, he does seem to have understood the exciting possibilities opened up by an understanding of the principles of light:

“This part of optics, when well understood, shows us how we may make things a very long distance off appear as if placed very close, and large near things appear very small, and how we may make small things placed at a distance appear any size we want, so that it may be possible for us to read the smallest letters at incredible distances, or to count sand, or seed, or any sort of minute objects.”

In other words, he envisioned the twin invention of the telescope and microscope, still 350 years in the future.

When you notice how others have a habit of portraying the progress of scientific thought as a mental jump from the Greeks of 300 BC to the Renaissance of 1500 AD, think of Grosseteste. The medieval thinkers brought Greek thought into the Christian intellectual world, reflected on it, gave it a proper home, and developed it. They disagreed with Aristotle on some issues, but they thought about his ideas.

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If the task of the natural scientist is to notice the universe, it will make sense to consider some of the things that prevent us from noticing. Here is a list of four sources of error, “the four chief hindrances to the understanding of truth,”  and I challenge you to guess the name and date behind the list:

  1. Submission to unworthy authority
  2. The influence of custom
  3. Popular prejudice
  4. The concealment of one’s own ignorance accompanied by an ostentatious display of knowledge.

The list is so delightfully complete:

  1. When we submit to an authority whose vision doesn’t really reach as far as what he is assumed to know, we close our eyes to what is directly in front of us. This is true in politics, but also in science where, for example, the influence of Darwin has long prevented men from taking hold of the most obvious consequence of the discovery of chromosomes. Clearly, when species within a genus have different chromosome counts, it follows that the new species could not have evolved gene by gene, for a new chromosome always involves many genes.
  2. You may think that science, dominated as it presently is by experiment, must be free of the influence of custom. But in fact, there was a whole generation after Einstein when his calculation of the speed of light was corroborated by one experimenter after another because they could not bring themselves to admit that they had found a different answer from the greatest physicist (as they thought) of the twentieth century. When someone finally printed his actual observations, a chorus of voices admitted their self-suppressed accord.
  3. The deep assumptions of our time in history are hard to question. The evidence for a finite universe was obvious and under discussion for hundreds of years, but simply did not “take” in most men’s minds, because there was too strong an image of eternity in the stars and too strong an academic prejudice against a finite universe. LeMaitre was despised and scorned for his challenge to this prejudice, but it’s over now. The universe is finite in time. Oh, there are hold-outs, including Stephen Hawking; but the stranglehold of a prejudice against an eternal universe is broken.
  4. Ahhh, humility! How many times, and in how many fields, do we noisily cover our vast ignorance with our little knowledge.

This list comes from Roger Bacon, 1214-1294, a medieval philosopher approximately contemporary with St. Thomas Aquinas, though a little longer-lived and born a little earlier.


For the sake of those who may faintly remember the name Francis Bacon, a little disambiguation is in order:

Roger Bacon and Francis Bacon were both:

  • English philosophers
  • Who emphasized the importance of observation
  • And who therefore have each been considered the father of scientific method

Nevertheless, they differed profoundly:

  • Roger Bacon was a Franciscan monk who lived in the 13th century, a contemporary of Albertus Magnus, Thomas Aquinas, and Robert Grossteste, and a famous and much-admired teacher at the University of Oxford and then the University of Paris. He wrote a treatise on magnetism that was the best work in the field for 300 years, until William Gilbert, a younger contemporary of Francis Bacon, took up the topic again.
  • Francis Bacon, quite a worldly man, lived in the 16th century, a contemporary of Shakespeare, Galileo, and Queen Elizabeth I. He retained royal favor during a period when Catholics were strongly persecuted, and his remarks about religion are consistent with that position. He is considered a believer because he wrote things like: “They that deny a God destroy man’s nobility; for certainly man is of kin to the beasts in his body; and, if he be not of kin to God by his spirit, he is a base and ignoble creature.”

Pathetic. If the main thrust of your argument for the existence of God is your own nobility, I can’t think of anything polite to say.

And despite whatever Francis Bacon said about experimental science, he never actually did any.

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