The Middle Ages were long centuries of stability in the intellectual world. All scientific and philosophical expression was monitored extensively by, and most often produced from within, the Church. During the Middle Ages, the Church ruled conclusively on a number of truths about the natural world, which it claimed were undeniable. These alleged truths were produced by Biblical study and the widely accepted Aristotelian system, which became official Church doctrine. The Aristotelian system defined the laws of physics erroneously in many cases. It claimed that the rate of fall of an object was determined by its weight, held that matter was constructed out of four possible elements, with different matter containing different combinations of these four, and described the universe as the Greek astronomer Ptolemy had described it, as a static and finite thing in which the Earth occupied the central position, with the sun and planets in revolution and the distant stars inhabiting its farthest edges. The physicians of the period considered that the human body contained four different kinds of liquid and that illness was caused by the imbalance of these 'humors.' These truths went generally unquestioned for years, backed up by the teachings of the Church and the common teaching of the educational institutions of the era.
With the rise of the Renaissance, new interest sparked in reference to the physical world. In part boosted by the spirit of geographical exploration, which dominated Europe and provided many new specimens for study and experimentation, the artists and thinkers of the Renaissance were infused with the desire to know and portray reality, prompting a dramatic rise in scientific exploration. Botany and biology flourished, as artists sought to better understand their subjects. This focus on the investigation of reality naturally began to create questions regarding the accepted Aristotelian norms. However, learning institutions continued to preach the Aristotelian system and the Church reinforced the dependence on past authority, thus, to an extent, drowning out the spirit of inquiry and doubt. The Protestant Reformation, begun by Martin Luther in 1517, radically transformed the theological and political landscape of Europe. Many Europeans began to question the authority of the Church. Indeed, a large faction broke away from the Church, in doing so breaking free from the restriction of intellectual progress. The fierce censorship of the Church's response to the Reformation, the Counter- Reformation, further pushed people from the Catholic fold and appeared to many as foolishly protective of it's outdated doctrines. In this atmosphere the Scientific Revolution blossomed, and the Aristotelian system fell.
By breaking the hold of the Aristotelian system, the Scientific Revolution opened the door to modern science. Much of the work done during the latter sixteenth and seventeenth century is still considered the foundation of the major fields of modern science, including physics, chemistry, biology, and astronomy. The Scientific Revolution left the world with a more logical description of physics, in which the laws of motion and gravity were well understood, setting the stage for many future breakthroughs and inventions. In the field of biology, where much had been left to mysticism until the seventeenth century, thinkers of the Scientific Revolution made great strides, pushing understanding of the human body to unprecedented heights. Out of this knowledge sprung the advancement of prevention and treatment for illness, a field that grew markedly after the Scientific Revolution. Perhaps the largest advance of the Scientific Revolution occurred in astronomy. Fueled by better understanding of physics and math (Isaac Newton's explanation of the motions of heavenly bodies relied heavily on his development of the mathematical field of calculus), astronomers unlocked the door to the universe.
Born out of the Scientific Revolution was the Enlightenment, which applied the scientific method developed during the seventeenth century to human behavior and society during the eighteenth century. The Scientific Revolution influenced the development of the Enlightenment values of individualism because it demonstrated the power of the human mind. The ability of scientists to come to their own conclusions rather than deferring to instilled authority confirmed the capabilities and worth of the individual. The power of human beings to discern truth through reasoning influenced the development of the Enlightenment value of rationalism. Such influences, combined with the decreasing reliance on the traditional teachings of the Church, led to a period of philosophical activity unparalleled in modern times.