Nous - Early Modern Philosophy

Early Modern Philosophy

The so-called "early modern" philosophers of western Europe in the 17th and 18th centuries established arguments which led to the establishment of modern science as a methodical approach to improve the welfare of humanity by learning to control nature. As such, speculation about metaphysics, which can not be used for anything practical, and which can never be confirmed against the reality we experience, started to be deliberately avoided, especially according to the so-called "empiricist" arguments of philosophers such as Bacon, Hobbes, Locke and Hume. The Latin motto "nihil in intellectu nisi prius fuerit in sensu" (nothing in the intellect without first being in the senses) has been described as the "guiding principle of empiricism" in the Oxford Dictionary of Philosophy. (This was in fact an old Aristotelian doctrine, which they took up, but as discussed above Aristotelians still believed that the senses on their own were not enough to explain the mind.)

These philosophers explain the intellect as something developed from experience of sensations, being interpreted by the brain in a physical way, and nothing else, which means that absolute knowledge is impossible. For Bacon, Hobbes and Locke, who wrote in both English and Latin, "intellectus" was translated as "understanding". Far from seeing it as secure way to perceive the truth about reality, Bacon, for example, actually named the intellectus in his Novum Organum, and the proœmium to his Great Instauration, as a major source of wrong conclusions, because it is biased in many ways, for example towards over-generalizing. For this reason, modern science should be methodical, in order not to be misled by the weak human intellect. He felt that lesser known Greek philosophers such as Democritus "who did not suppose a mind or reason in the frame of things", have been arrogantly dismissed because of Aristotelianism leading to a situation in his time wherein "the search of the physical causes hath been neglected, and passed in silence". The intellect or understanding was the subject of Locke's Essay Concerning Human Understanding.

These philosophers also tended not to emphasize the distinction between reason and intellect, describing the peculiar universal or abstract definitions of human understanding as being man-made and resulting from reason itself. Hume even questioned the distinctness or peculiarity of human understanding and reason, compared to other types of associative or imaginative thinking found in some other animals. In modern science during this time, Newton is sometimes described as more empiricist compared to Leibniz.

On the other hand, into modern times some philosophers have continued to propose that the human mind has an in-born ("a priori") ability to know the truth conclusively, and these philosophers needed to argue that the human mind has direct and intuitive ideas about nature, and this means it can not be limited entirely to what can be known from sense perception. Amongst the early modern philosophers, some such as Descartes, Spinoza, Leibniz, and Kant, tend to be distinguished from the empiricists as rationalists, and to some extent at least some of them are called idealists, and their writings on the intellect or understanding present various doubts about empiricism, and in some cases they argued for positions which appear more similar to those of medieval and classical philosophers.

The first in this series of modern rationalists, Descartes, is credited with defining a "mind-body problem" which is a major subject of discussion for university philosophy courses. According to the presentation his 2nd Meditation, the human mind and body are different in kind, and while the human body works like a clockwork mechanism, and its workings include memory and imagination, the real human is the thinking being, a soul. Descartes explicitly refused to divide this soul into its traditional parts such as intellect and reason, saying that these things were indivisible aspects of the soul. Descartes was therefore a dualist, but very much in opposition to traditional Aristotelian dualism. In his 6th Meditation he deliberately uses traditional terms and states that his active faculty of giving ideas to his thought must be corporeal, because the things perceived are clearly external to his own thinking and corporeal, while his passive faculty must be incorporeal (unless God is deliberately deceiving us, and then in this case the active faculty would be from God). This is the opposite of the traditional explanation found for example in Alexander of Aphrodisias and discussed above, for whom the passive intellect is material, while the active intellect is not. One result is that in many Aristotelian conceptions of the nous, for example that of Thomas Aquinas, the senses are still a source of all the intellect's conceptions. However, with the strict separation of mind and body proposed by Descartes, it becomes possible to propose that there can be thought about objects never perceived with the body's senses, such as a thousand sided geometrical figure. Gassendi objected to this distinction between the imagination and the intellect in Descartes. Hobbes also objected, and according to his own philosophical approach asserted that the "triangle in the mind comes from the triangle we have seen" and "essence in so far as it is distinguished from existence is nothing else than a union of names by means of the verb is". Descartes, in his reply to this objection insisted that this traditional distinction between essence and existence is "known to all".

His contemporary Blaise Pascal, criticised him in similar words to those used by Plato's Socrates concerning Anaxagoras, discussed above, saying that "I cannot forgive Descartes; in all his philosophy, Descartes did his best to dispense with God. But Descartes could not avoid prodding God to set the world in motion with a snap of his lordly fingers; after that, he had no more use for God."

Descartes argued that when the intellect does a job of helping people interpret what they perceive, not with the help of an intellect which enters from outside, but because each human mind comes into being with innate God-given ideas, more similar then, to Plato's theory of anamnesis, only not requiring reincarnation. Apart from such examples as the geometrical definition of a triangle, another example is the idea of God, according to the 3rd Meditation. Error, according to the 4th Meditation, comes about because people make judgments about things which are not in the intellect or understanding. This is possible because the human will, being free, is not limited like the human intellect.

Spinoza, though considered a Cartesian and a rationalist, rejected Cartesian dualism and idealism. In his "pantheistic" approach, explained for example in his Ethics, God is the same as nature, the human intellect is just the same as the human will. The divine intellect of nature is quite different from human intellect, because it is finite, but Spinoza does accept that the human intellect is a part of the infinite divine intellect.

Leibniz, in comparison to the guiding principle of the empiricists described above, added some words ""nihil in intellectu nisi prius fuerit in sensu, nisi intellectus ipsi" (nothing in the intellect without first being in the senses except the intellect itself). Despite being at the forefront of modern science, and modernist philosophy, in his writings he still referred to the active and passive intellect, a divine intellect, and the immortality of the active intellect.

Berkeley, partly in reaction to Locke, also attempted to reintroduce an "immaterialism" into early modern philosophy (later referred to as "subjective idealism" by others). He argued that individuals can only know sensations and ideas of objects, not abstractions such as "matter", and that ideas depend on perceiving minds for their very existence. This belief later became immortalized in the dictum, "esse est percipi" ("to be is to be perceived"). As in classical and medieval philosophy, Berkeley believed understanding had to be explained by divine intervention, and that all our ideas are put in our mind by God.

Hume accepted some of Berkeley's corrections of Locke, but in answer insisted, as had Bacon and Hobbes, that absolute knowledge is not possible, and that all attempts to show how it could be possible have logical problems. Hume's writings remain highly influential on all philosophy afterwards, and for example considered by Kant to have shaken him from an intellectual slumber.

Kant, a turning point in modern philosophy, agreed with some classical philosophers and Leibniz that the intellect itself, although it needed sensory experience for understanding to begin, needs something else in order to make sense of the incoming sense information. In his formulation the intellect (Verstand) has "a priori" or innate principles which it has before thinking even starts. Kant represents the starting point of German idealism and a new phase of modernity, while empiricist philosophy has also continued beyond Hume to the present day.