The Aristotelian system was the broad term used to refer to the traditional view
of the world expressed during the age of Aristotle by the ancients, and
maintained and modified by the Church to fit with religious doctrine throughout
the Middle Ages. The Aristotelian system included
accepted truths about biology, physics, and most notably, astronomy. Many of
these "truths" were proven wrong during the Scientific Revolution.
Doctrine of Uniformity
The doctrine of uniformity was an enormous step in the quest to integrate
physics and astronomy. Developed by Galileo in his Dialogue on the Two
Chief Systems of the World, the doctrine of uniformity states that
corresponding causes produce corresponding affects throughout the universe.
Thus, terrestrial physics may be used to explain the motion of heavenly bodies.
The term geocentric describes the theory on the organization of the universe
presented by Ptolemy of ancient Greece, and incorporated into the
Aristotelian system, which claims that the earth is the center of the solar
system and that the sun and other planets orbit around it.
The term heliocentric describes the correct theory, first posed by Nicolas
Copernicus, that the Earth is simply one of several planets which orbit the
The Inquisition was the section of the Catholic Church devoted to the
maintenance of Church doctrine by the discovery and punishment of heretics. It
was the Inquisition which warned Galileo to abandon his theories after the
publication of Messenger of the Heavens, and the Inquisition which
committed him to house arrest after his publication of Dialogue on the Two
Chief Systems of the World. Read the SparkNote on Galileo.
Kepler's Laws of Planetary Motion
Though Johannes Kepler was unable to conceive a working model of the
universe, he did contribute the three laws of planetary motion, all of which
were at least somewhat accurate, and all of which were used extensively by
Isaac Newton in his work. They are:
1. The planets move around the sun not in circles, but ellipses.
2. Planets do not move uniformly, but in such a manner that a line drawn from a
planet to the sun sweeps out an equal area of the ellipse of its orbit in equal
time, even if the ellipse is not perfectly centered on the sun.
3. The squares of the periods of the planets' orbits are proportional to the
cubes of their distances from the sun.
The physics of Kepler's rules and of orbits in general are covered in the
SparkNote on Kepler.
The Royal Society of London brought together the greatest minds of the region in
efforts to advance science through cooperation. The Royal Society of London,
and other scientific societies that grew up in Europe during the later
seventeenth century, contributed greatly to the scientific progress made during
The cornerstone of Newton's explanation of the organization of the universe,
the law of universal gravitation states that every particle of matter attracts
every other particle with a force proportional to the product of the two masses
and inversely proportional to the square of the distance between them.
Read the SparkNote on the physics of Newton's work.
and on Newton's life.
Bacon (1561-1626) was one of the great philosophers of the Scientific Revolution. His thoughts on logic
and ethics in science and his ideas on the cooperation and interaction of the various fields of science,
presented in his work Novum Organum, have remained influential in the scientific world to this day.
Giovanni Alfonso Borelli
Borelli (1608-1679) was the foremost thinker of the era on human mechanics. His 1680 work, On the
Motion of Animals, is widely recognized as the greatest early triumph of the application of mechanics
to the human organism.
Boyle (1627-1691), a successful physicist at Oxford college, worked with his colleague Robert Hooke to
discern the properties of the air, experimenting with air pressure and the composition of the atmosphere.
Boyle proved that only a part of the air is used in respiration and combustion, and is thus credited with
the discovery of oxygen. Boyle's further work touched on the beginnings of the study of matter on the
Tycho Brahe (1546-1601) was a great astronomical observer, and made accurate and long-term records of his
observations, from which he derived his view of the structure of the solar system, in which the moon and
sun orbited the Earth and the remaining planets orbited the sun. While incorrect, his scheme was as
viable by the knowledge of the time as was that of Nicolas Copernicus.
A German, in 1530 Brunfels (1488-1534) was the first to produce a major work on plants. However, he fell
victim to a blunder made by many botanists of the time. In reverence for the ancients, whose botanical
studies were widely revered, in his study he attempted to compare his findings to those of the Greeks and
Romans. The differences in plant life produced by the variation in geography meant that comparison was
futile, and confusion resulted in the field of botany, clouding the work of many of Brunfels' immediate
A renegade Italian monk, Bruno (1548-1600) published three works--The Ash-Wednesday Supper,On
Cause, Principle, and Unity, and On the Infinite Universe and its Worlds--in which he laid out
his philosophy that the universe was of infinite size, and that the Earth, sun, and planets were all
moving constantly within it, and were by no means located at its center.
Copernicus (1473-1543) was an avid student of astronomy, and in 1543 published De Revolutionibus
Orbium Coelestium. In this treatise, he presented the heliocentric theory, which rested on the
revolutionary notion that the Earth orbited the sun.
Descartes (1596-1650) was one of the greatest minds of the Scientific Revolution. The inventor of
deductive reasoning, Descartes was a failure as a practical scientist, but a success as a mathematician,
uniting number and form in his work Geometry, which described how the motion of a point could be
mapped graphically by comparing its position to planes of reference.
A Botanist of the sixteenth century, Fuchs (1501-1566) produced a guide to collecting medical plants that
is considered a landmark in the history of natural observation. His woodcut prints are the most
beautiful and accurate of the period.
An ancient Greek physician, Galen's (129-199) work was the centerpiece of traditional biology and anatomy
that had lasted through the Middle Ages.
Galileo (1564-1642) was the most successful scientist of the Scientific Revolution, save only Isaac
Newton. He studied physics, specifically the laws of gravity and motion, and invented the telescope
and microscope. Galileo eventually combined his laws of physics with the observations he made with his
telescope to defend the heliocentric Copernican view of the universe and refute the Aristotelian
system in his 1630 masterwork, Dialogue on the Two Chief Systems of the World. Upon its
publication, he was censored by the Catholic Church and sentenced to house arrest in 1633, where he
remained until his death in 1642. Read the SparkNote on Galileo.
Hartlib (1600-1662), a London scientist and socialite, first conceived of the creation of the Royal
Society of London, and was instrumental in its eventual founding in 1662.
Through dissection, Harvey (1578-1657) was the first to demonstrate that the circulation of blood through
the human body is continuous, rather than consisting of different types circulating through the veins and
arteries, as had been previously assumed by the ancient Greek physician, Galen.
Kepler (1571-1630) studied the orbits of the planets and sought to discern some grand scheme that defined
the structure of the universe according to simple geometry. Though he was unable to do accomplish his
goal, he did come up with the laws of planetary motion, which explained the orbital properties of
planets, and factored extensively into Isaac Newton's later work. Read the SparkNotes
on Newton and Kepler.
A botanist of the seventeenth century, Edme Mariotte (1620-1684) sought to explain sap pressure in plants
by describing a mechanism by which plants permit the entrance but not the exit of liquid.
A well known microscopist, Malpighi (1628-1694) studied insects in depth and developed a theory of plant
circulation which, though flawed, inspired interest in the field. Malpighi's studies were immortalized
when his name was given to the main excretory organ of arthropods, the malpighian
In 1594, John Napier(1550-1617) invented the mathematical tool of
logarithms. He spent the next 20 years of his
life developing his theory and computing an extensive table of logarithms to aid
in calculation. In 1614, he published Description of the Marvelous Canon of
Logarithms, which contained the fruits of these labors.
Perhaps the most influential scientist of all time, Newton (1642-1727) took the current theories on
astronomy a step further and formulated an accurate comprehensive model of the workings of the universe
based on the law of universal gravitation. Newton explained his theories in the 1687 revolutionary work
Philosophia Naturalis Principia Mathematica, often called simply the Principia. This work
also went along way toward developing calculus. Read the SparkNote on
An ancient Greek astronomer and mathematician, Ptolemy's geocentric views on
the structure of the universe dominated astronomy until the Scientific
Santorio (1561-1636) was one of the first to apply the evolving physical philosophy of the Scientific
Revolution to animal biology. His experiments laid the groundwork for the study of metabolism and the
physical and chemical processes of the human body.
Stevin (1548-1620) worked with geometry during the late sixteenth century, applying it to the physics of
incline planes and the hydrostatic surface tension of water. Additionally, he introduced the decimal
system of representing fractions, an advance which greatly eased the task of calculation.
One of the earliest chemical biologists, Sylvius (1614-1672) introduced the idea of chemical affinity to
explain the human body's use of salts. He and his followers contributed greatly to the study of
digestion and body fluids.
Torricelli (1608-1647) invented the barometer, to measure air pressure, in 1643. This was a large step
in the understanding of the properties of air, and the basic structure of the barometer remains the same
today. A unit of pressure, called a Torr, is named after him.
Jan Baptist van Helmont
Van Helmont (1580-1644) was an alchemist who largely abided by the accepted truths of the Middle Ages,
but in many ways broke from the past and moved forward. He experimented on the role of water in the
growth of plants, claiming that plants drew all of their substance from water. He also demonstrated that
gases, though they commonly appeared quite similar, could be quite different in character. In fact, van
Helmont invented the word "gas." Read the SparkNote on Gases.
As a student and professor in Belgium and Paris, Vesalius (1514-1564) was educated in the anatomical
works and theories of the ancient Greek physician Galen, whose views on anatomy had long been the
standard in Europe. Vesalius questioned Galen's authority, and published On the Fabric of the Human
Body in 1543. It is considered the first great modern work of science, and the foundation of modern
Viete (1540-1603) was one of the first to use letters to represent unknown numbers. In 1591, he invented
analytical trigonometry using this algebraic method.
Otto von Guericke
In 1656, Otto von Guericke (1602-1686) invented the air pump, and did the first experiments with vacuums.
In the process he demonstrated many of the properties of gases, such as the (until then) disputed claim
that they did, in fact, have weight.
Wallis' work, Arithmetica Infinitum, published in 1655, set the stage for the invention and
development of differential calculus: this work went on to be one of Isaac Newton's major influences.
Wallis (1616-1703) was the first mathematician to apply mathematics to the operation of the tides, and
also invented the symbol used to denote infinity.