The 17th century begins with a scientific revolution and ends with a political revolution in England (1688) from which the modern liberal state is born. The theocratic monarchy is replaced by the constitutional monarchy.Locke will justify philosophically the revolution, which places reason above tradition and faith.

The Mechanism of the 17th Century: Locke and Descartes

Baroque dominates the century. The painting is filled with darkness, shadows, contrasts. In architecture the pure and straight Renaissance lines are broken, twisted, the balance gives way to movement, to passion. The baroque and the body. Presence of death, of the double. The difference between reality and dream. The great theatre of the world, the world as representation (Calderón de la Barca). The genre of the novel is consolidated ( Don Quixote appears in 1605; during the XVIIth the picaresque novel triumphs). In painting, Velázquez (1599-1660).

The conception of the world becomes scientific, mathematical and mechanistic. Scientists have demonstrated the mechanical nature of celestial and terrestrial phenomena and even of animal bodies (End of Animism ).

A scientific and intellectual revolution

The scientific revolution meant moving the earth from the center of the universe. The revolution began in 1453 with the publication of the Revolution of the Celestial Orbits by Copernicus , who proposed that the Sun, and not the Earth, was the centre of the solar system. Copernicus’ physics was, however, Aristotelian, and his system lacked empirical proof. Galileo Galilei (1564-1642) was the most effective advocate of the new system, underpinning it with his new physics (dynamics), and providing telescopic evidence that the moon and other celestial bodies were no more “heavenly” than the Earth. However, Galileo believed, like the Greeks, that the movement of the planets was circular, even though his friend Kepler proved that the planetary orbits were elliptical. The definitive unification of celestial and terrestrial physics took place in 1687 with the publication of Newton’s Principia Mathematica .

The laws of motion of Isaac Newton reaffirmed the idea that the universe was a big machine. This analogy had been proposed by Galileo and also by René Descartes, and became the popular conception at the end of this century.

As a consequence, the idea of an active and vigilant God, by whose express intention every last leaf of a tree fell, was reduced to that of an engineer who had created, and maintained, the perfect machine.

From the very birth of modern science, two opposing conceptions are present: an old Platonic tradition supported a pure and abstract science, not subject to a criterion of utility ( Henry More : ” science should not be measured by the help it can give you on your back, bed and table “) . Wundt and Titchener will support this viewpoint for Psychology. In this century, instead, an idea of utilitarian, practical, applied science is developed, whose most vigorous defender is Francis Bacon. In the following century, this tradition is firmly established in England and North America, and is oriented towards anti-intellectualism.

The scientific revolution, in either of the two conceptions, re-edits an old atomist idea according to which some sensory qualities of objects are easily measurable: their number, weight, size, shape and movement. Others, however, are not, such as temperature, colour, texture, smell, taste or sound. Since science must be about the quantifiable, it can only deal with the first type of qualities, called primary qualities, which atomists had attributed to atoms themselves. The secondary qualities are opposed to the primary ones because they exist only in human perception, resulting from the impact of atoms on the senses.

Psychology would be founded, two centuries later, as a study of the consciousness and, therefore, included in its object all the sensory properties . Later on, behaviorists will consider that the object of psychology is the movement of the organism in space, rejecting the rest. Movement is, of course, a primary quality.

Two philosophers represent in this century the two classical tendencies of scientific thought: Descartes for the rationalist vision, with a conception of pure science, and Locke for the empiricist, with a conception of utilitarian or applied science.