This is a sort of footnote to my last post in which I criticised science writer Tim Radford for propagating myths about the reception of heliocentricity in the sixteenth-century. Now a second truly legendary astronomer and science writer, John Gribbin, has turned up in the comments and shown that he also lives in the nineteenth-century, as far as history of science is concerned, when John William Draper and Andrew Dickson White created the myth of an eternal war between science and religion and presented Giordano Bruno and Galileo Galilei, alongside lesser lights such as Michael Servetus and Marco-Antonio de Dominis, as the scientific victims of Christian persecution.

Rushing in where angels fear to tread Gribbin sought to defend Radford’s honour with the following comment:

As a card-carrying pedant, I would point out that Tim says “ideas like that”, not “that idea”. Which makes Bruno relevant, whether you like it or not.

Now I appreciate Mr Gribbin’s attempt to help his friend and colleague but in doing so he has only displayed his own ignorance of the material. There was a very good reason why I ended my last post with the following tongue in cheek warning:

P.S. If anybody mentions either Giordano Bruno or Galileo Galilei in the comments I will personally hunt them down and beat them to death with a rolled up copy of The Guardian.

No modern historian of science, knowledgeable of the history of astronomy in the Early Modern Period, would follow Draper and White in viewing Bruno as a martyr of science. This is a myth that has been thoroughly debunked and which is, these days, usually only dug up by historically ignorant gnu atheists and others of that ilk, as a weapon with which to beat the Catholic Church around the head. As John Gribbin has walked straight into the trap we will just briefly examine why the Church committed Giordano Bruno to the flames.

A Dominican monk, Bruno came under suspicion of heresy and fled his Southern Italian monastery in 1576. He spent the next sixteen years wandering around Europe blowing his own trumpet, generally annoying people and pissing off the authorities, both civil and religious, wherever he went. Returning to Italy he landed, not unsurprisingly in the clutches of the Roman Inquisition. He was held prisoner and interrogated for seven years before being tried for heresy, found guilty, and executed by burning at the stake in 1600. The proceedings of his trial have disappeared so it is not known what exactly he was found guilty of but summary was discovered in 1940 and a list of the charges against him is known:

holding opinions contrary to the Catholic faith and speaking against it and its ministers;

holding opinions contrary to the Catholic faith about the Trinity, divinity of Christ and Incarnation;

holding opinions contrary to the Catholic faith pertaining to Jesus as Christ;

holding opinions contrary to the Catholic faith regarding the virginity of Mary, mother of Jesus;

holding opinions contrary to the Catholic faith about both Transubstantiation and Mass;

claiming the existence of a plurality of worlds and their eternity;

believing in metempsychosis and in the transmigration of the human soul into brutes;

dealing in magics and divination.

Now this list is not hidden away somewhere, I just borrowed it from the Wikipedia Bruno article, so Mr Gribbin could have consulted it himself. He would of course pounce on the sixth item on the list gleefully crying I told you so, but let us examine if he should be so sure of being right.

Given the fact that Bruno was accused of breaching almost every single central doctrine of the Catholic Church did this one point of highly speculative cosmology really play such a central role in his conviction and subsequent execution, I hardly think so. In fact I don’t think it played much of a role at all compared to his denying the divinity of Christ and the virgin birth. However there is more.

Bruno’s claiming the existence of a plurality of worlds and their eternity has little or nothing to do with Copernicus’ heliocentric theory the original statement for which Tim Radford claimed one could be condemned to the stake. Copernicus proposed a finite sun centred cosmos, Bruno speculated about an infinite universe filled with homogenously distributed infinite sun each with their own populated planets and no centre. The two proposals don’t have an awful lot in common. Copernicus expressly refused to enter the discussion as to whether the cosmos was finite or infinite, and never speculated about other inhabited planets. He, as a good Catholic cleric, would definitely have rejected an eternal universe as this contradicted the Creation. What about the two leading Copernican of Bruno’s own times? Kepler explicitly rejected Bruno’s infinite universe and infinite suns and in doing so brought the earliest known argument against Olbers’ paradox. Galileo simply ignored him. I think it is safe to say that the cosmological statements that were included in Bruno’s indictment were not ideas like Copernicus’ heliocentric theory, as claimed by Gribbin.

Gribbin’s claim also suffers from another problem. The reason why Bruno’s cosmological speculations were included in his indictment was very clearly theological and not scientific. As already mentioned if, as Bruno claimed, the universe were eternal then there could be no Creation, highly heretical. In fact this was one of the central reasons why the Catholic Church rejected the Greek philosophy of Atomism. Secondly if there were infinite populated worlds there would be serious problems with the doctrine of salvation through Jesus. If he was the only Son of God did he visit all of the infinite populated planets, simultaneously, one after the other? Or were there infinite Jesuses? Did he only save the earth? Then what about the other planets? A really tangled mess for the Catholic theologians! As with Galileo in 1615 if Bruno had had anything remotely like proof for his cosmology he might have had something he could argue with but he didn’t, all he had was pure unscientific, unsubstantiated speculation. As I sated in earlier posts Bruno’s cosmological speculations were anything but scientific and anything but accurate. As far as we know the universe is finite and not infinite, it had a starting point and will almost certainly have an end. There are neither infinite stars (suns) nor infinite planets and those that there are, are not distributed homogenously. To stylise Bruno as a scientific martyr, as Draper/White did in the nineteenth-century and as John Gribbin apparently still wants to do, boarders on the grotesque.