On this day in history, February 17 in the year 1600, the philosopher Giordano Bruno was burned at the stake.  

In the introduction to their 1977 translation of Bruno's 1584 text The Ash Wednesday Supper, Edward A. Gosselin and Lawrence S. Lerner write that "Giordano Bruno is one of those semi-legendary figures of whom nearly every educated person has heard the name and very little more" (11).  

They go on to say that the commonly-understood "myth" of Bruno's life and importance, while based in the true details of his life, leaves out the full complexity both of the man and the significance of his philosophy.  They summarize "the Bruno myth" as follows:
An itinerant renegade friar, Bruno defied contemporary ecclesiastical authorities and doctrines.  In addition, he vehemently rejected the commonly held Ptolemaic belief that the earth lay at the center of the universe, and engaged in mystical speculation which centered about his pioneering support of the Copernican view.  In connection with his Copernican beliefs, he held also that the universe contains an infinite number of worlds populated with intelligent beings.  On account of these teachings, Bruno was tried for heresy by the Inquisition and burned at the stake in 1600.  He thus became the first martyr of modern science at the hands of the Church, and thereby a precursor of Galileo.  The moral of this nineteenth-century story is that Science, the bearer of knowledge, struggles to an inevitable victory over the Church, the champion of ignorance and superstition.  11-12.
Gosselin and Lerner write that while the "facts in this myth are true" they are "sketchy to the point of poverty and generally misleading in their emphasis" (12).  Rather, they note that while Bruno was among the first to support the Copernican revolution, his emphasis was on its philosophical implications, which run far beyond the merely scientific details of which heavenly object orbits which.  It was Bruno's brilliant insight to perceive that the motion of the bodies in the universe, including the earth, had implications which impacted every aspect of human existence.  Gosselin and Lerner write: "For these movements called upon the whole encyclopedia of human knowledge in their efforts to restore the lost harmonia mundi"(13).  

In his introduction to the collection Giordano Bruno: Cause, Principal and Unity, and Essays on Magic, Alfonso Ingegno writes that Bruno's Ash Wednesday Supper discussion of the work and significance of Copernicus can help us perceive the scope of Bruno's philosophy. Ingegno writes:
Copernicus was primarily a mathematician -- his interest was directed towards astronomy rather than towards natural philosophy, and in this sense his work needed to be further developed.  Certainly he started from a correct and significant physical presupposition, the earth's motion, but he sought only a mathematical description of the movements of the heavens.
In contrast, Bruno presents himself as a natural philosopher, as the one who is destined to become the authentic interpreter of Copernicus' discovery and is called to draw out the conclusions from it, beginning with the physical ones.  [. . .]  Thus in The Ash Wednesday Supper Copernicus becomes the inspired one to whom the gods have entrusted a message, the importance and significance of which he has not realized; he is like a blind fortune teller for whom Bruno acts as the authentic interpreter.  ix.
Ingegno goes on to give a taste of the profundity of Bruno's vision:
The philosopher, therefore, is summoned on a metaphorical journey across the heavens to discover that the traditional crystalline spheres are only a vain fiction, that there is no upper limit to the physical world and thus no end to his journey, and that what opens out in front of him is an infinite space.  The philosopher shows us that the divinity is present in us and in our planet no less than in every other heavenly body, that it is not situated beyond the imaginary limit of a closed and finite universe, in a place which makes it accessible to man.
In other words, Bruno perceived that the work of Copernicus changed everything, because it meant that divinity is not "situated beyond the imaginary limit of a closed and finite universe" (that is to say, that the Eternal did not dwell in a remote location, above the outermost of the "crystalline spheres" of heaven), but that "divinity is present in us" and can be found in a place that is accessible to every man and woman.

Bruno saw this vision as enabling the reconciliation of mankind, and as offering the possibility for overcoming the violent religious wars and controversies which were wracking Europe (and which would ultimately lead to his own violent murder at the hands of religious authorities).  Bruno perceived that Copernicus had broken through the mental fiction upon which was based a system of violence and suppression that had kept human beings in ignorance and poverty, and that the downfall of this fiction opened up the gate to the reconciliation of all human knowledge, and a return to an ancient harmony that had been lost.  

In her groundbreaking 1964 work, Giordano Bruno and the Hermetic Tradition, Frances A. Yates argues that Bruno thus revived the ancient vision of the Hermetic Neoplatonists of the second and third centuries AD, a vision that was eventually crushed by the rise of ecclesiastical and literal Christianity.  It was this vision, rather than his support for the Copernican system, which led to his execution, according to Yates.  She writes that Bruno was perceived as "particularly dangerous because he had had a religious mission"(445).  "Bruno's universal reform," she says, "aimed at returning to a supposedly pre-Christian Hermetic Egyptianism.  Bruno himself, however, would not have regarded this as necessarily anti-Christian since, as we have seen, he entertained the strange hope that the reform would come within an existing framework"(445).

As Alfonso Ingegno tells us, "More than any previous thinker, then, Bruno is aware of the fact that the fall of Aristotelian cosmology implies the end of traditional metaphysics."  But, he thought that others would embrace the metaphysical implications of the death-blow that Copernican science was dealing to the Aristotelian cosmology (of a fixed earth), and in this he was fatally mistaken.

Bruno's philosophy was far-ranging and all-encompassing.  His insight that the universe was infinite, and that it was composed of minute "seeds" which bonded together temporarily and then dissolved to form again, he perceived to have ramifications that ranged from the fate of the soul after the death of the body (he wrote: "Death is nothing more than [. . .] a disintegration.  No spirit and no body ever perishes; rather there is only a continual change of combinations and actualizations," Cause, Principle and Unity) to the concept of "social binding," which is very much analogous to what we might today call "mind control" (he wrote: "even if there were no hell, the thought and imagination of hell without a basis in truth would still really produce a true hell, for fantasy has its own kind of truth," and ""No bonds are eternal.  Rather, things alternate between bondage and freedom, between being bonded and escaping from a bond, or they transfer from one type of bond to another," Cause, Principle and Unity). 

He wrote an entire treatise discussing the ways that the masses can be manipulated by psychological and magical bonds, and on recognizing and escaping from such bonds (entitled De vinculus in genere, or Of bonds in general, it can be found along with other works by Bruno -- albeit in Latin -- here; The Ash Wednesday Supper can be found in English online here).  The quotations in the previous paragraph can be found in this excellent online review by Sonya Bahar of Ingrid Rowland's 2009 biography of Giordano Bruno. 

Ultimately, a philosopher as vast as Giordano Bruno cannot be encompassed, any more than can the infinite cosmos he proclaimed -- the infinite cosmos which the ancient Hermetic wisdom he espoused declares to be present inside every human being.