There were many natural philosophers, particularly in the West, who looked to al-Kindi for support in their defense of a combined intromission-extramission theory. Grosseteste, an early defender of such a combined theory, was in all likelihood familiar with al-Kindi's De aspectibus and probably had al-Kindi in mind when he wrote: "However, mathematicians and physicists, whose concerns is with those things that are above nature, ...maintain that vision is produced by extramission." Later in the thirteenth century Roger Bacon and John Pecham also appealed to the authority of al-Kindi to support their contention that rays issue from, as well as enter, the observer's eye.
John PeckhamRelated topics
above authority bacon century combined contention defender defense early enter extramission eye familiar issue john later likelihood mind natural nature support theory thirteenth vision well west things rogerRelated quotes
I was born in the Realms of Etiquette;
In early years, unprotected and poor.
Alone, I learnt to distinguish between Evil and Good;
Untutored, I toiled at bitter tasks.
The World's Law honours Learning and Fame;
Scholars prize marriages and Caps.
With these fetters I gyved my own hands;
Truly I became a much-deceived man.
At ten years old I learnt to read books;
At fifteen, I knew how to write prose.
At twenty I was made a Bachelor of Arts;
At thirty I became a Censor at the Court.
Above, the duty I owe to Prince and parents;
Below, the ties that bind me to wife and child.
The support of my family, the service of my country-
For these tasks my nature is not apt.
Bai Juyi
Perhaps the editor may be accused of nationality, when he says, that, taking the total merits of this work together, he prefers it to the early exertions of even the Italian muse, to the melancholy sublimity of Dante, and the amorous quaintness of Petrarca...Here indeed the reader will find few of the graces of fine poetry, little of the attic dress of the muse; but here are life and spirit, and ease and plain sense, and pictures of real manners, and perpetual incident and entertainment. The language is remarkably good for the time, and far superior in neatness and elegance even to that of Gawin Douglass, who wrote more than a century after.
John Barbour
Evolutionary psychology was the organizing framework-the source of "explanatory adequacy” or a "theory of the computation”-that the science of psychology had been missing. Like vision and language, our emotions and cognitive faculties are complex, useful, and nonrandomly organized, which means that they must be a product of the only physical process capable of generating complex, useful, nonrandom organization, namely, natural selection. An appeal to evolution was already implicit in the metatheoretical directives of Marr and Chomsky, with their appeal to the function of a mental faculty, and evolutionary psychology simply shows how to apply that logic to the rest of the mind.
Steven Pinker
The inversion theory has a long and fascinating history in the discussion of vertebrate origins. The founding version dates to the early nineteenth century and became the centerpiece of a movement often called "transcendental biology," and centered on the attempt to reduce organic diversity to one or a very few archetypal building blocks that could generate all actual anatomies as products of rational laws of transformation. Some of Europe's greatest thinkers participated in this grand, if flawed enterprise. Goethe, Germany's preeminent poet-scientist, tried to explain the varied parts of plants as different manifestations of an archetypal leaf.
Stephen Jay Gould
If the water flow down by a gradual natural channel, its potential energy is gradually converted into heat by fluid friction, according to an admirable discovery made by Mr Joule of Manchester above twelve years ago, which has led to the greatest reform that physical science has experienced since the days of Newton. From that discovery, it may be concluded with certainty that heat is not matter, but some kind of motion among the particles of matter; a conclusion established, it is true, by Sir Humphrey Davy and Count Rumford at the end of last century, but ignored by even the highest scientific men during a period of more than forty years.
William Thomson
