According to the Internet Encyclopedia of Philosophy, Benedict de Spinoza was among one of the most important of the post-Cartesian philosophers "who flourished in the second half of the 17th century" and dealt with the implications of free will, mathematics, and science in answering questions about the mind body problem first posed by Descartes. (Dutton, Internet Encyclopedia of Philosophy 2004) The Jewish Spinoza took up the originally Christian Cartesian notion of the body/mind duality and placed them in a deterministic theological context, freed of some of Descartes' concerns about proving the existence of God.
Spinoza, however, like Descartes, also stressed that the body and mind were of fundamentally different substances, that the latter essence of the mind was 'alien' somehow, or rather possessed elements that the body did not, because of the nature of cognition or thought. Spinoza also stated a deterministic view of life and human existence that subsumed both will and mind to larger natural forces." (152) He wrote. And, "the body cannot determine the mind to thinking, nor can the body determine the mind to motion, or anything else." (152)
Spinoza thus advocated a highly deterministic but amoral and irreligious mind and body dualism, whereby the human world was propelled by forces beyond human control, even though individuals might possess an illusion of free will because of the nature of the way people think and their brains are constructed. This is despite the fact that, "Spinoza came into the world" raised a religious Jew. "Born in 1632, he was the son of Marrano parents." But out of economic necessity, he left his study of the Talmud and came into his father's business. By traveling widely, he grew exposed, "most significantly," to the community of and contact "with so-called 'free-thinking' Protestants -- dissenters from the dominant Calvinism -- who maintained a lively interest in a wide range of theological issues, as well as in the latest developments in philosophy and science. This naturally included the work of Descartes, which was regarded by many in Holland to be the most promising of several alternatives to scholasticism that had emerged in recent decades. In order to discuss their interests, these freethinkers organized themselves into small groups; they called colleges, which met on a regular basis. Spinoza may have attended such meetings as early as the first half of the 1650's, and it is most likely here that he received his first exposure to Cartesian thought." (Dutton, Internet Encyclopedia of Philosophy, 2004)
Thus, despite his Jewish birth and theological upbringing, Spinoza's main influence was religiously, that of Protestant determinists, which he combined with a strong scientific emphasis on the forces of nature, in which humanity is merely an obedient tool. Yet even the moral influence of Calvinist silence and its dim view of human nature can be seen as when Spinoza muses, "Human affairs would be a far happier affair, if people had the ability to keep silent as well as to speak out." (154)
Social influences -- Before, Now, and After for Rousseau's Social Compact and the Sovereign
If Spinoza is a reflection of his philosophical exposure and times, Rousseau is clearly a reflection of his political times. (498) The Frenchman attempted to formulate a defense of freedom for all people, based upon an innate notion of human rights. "The problem is to find a form of association which will defend and protect with the whole common force the person and goods of each associate, and in which each, while uniting himself with all, may still obey himself alone, and remain as free as before." (498) In other words, the problem of politics is to prevent men and women from killing themselves in a rude and ruthless state of nature, yet still allow human beings to remain functioning and free. The 'before' period Rousseau reacted to was that of the philosophy of Hobbes, which demanded the sovereign ameliorate the excesses of human in-fighting and believed in a necessary curtailing of human freedom.
Thus, the 'now' Rousseau created, or the solution was the social compact, or what Rousseau called the Social Contract between sovereigns and ruled. "This is the fundamental problem" of human fighting "of which the Social Contract provides the solution." The solution was to create a contract, in other words, that could be dissolved if one party or the other violated its tenants, but there was a collective interest in the majority of the citizens as well as the single sovereign to uphold the compact. (498)
The sense that democracy is the best of all bad systems still remains today, as Rousseau concluded, "moreover, the alienation being without reserve, the union is as perfect as it can be, and no associate has anything more to demand: for, if the individuals retained certain rights, as there would be no common superior to decide between them and the public, each, being on one point his own judge, would ask to be so on all; the state of nature would thus continue, and the association would necessarily become inoperative or tyrannical." (498) The human desire to be king and to have all is kept in check with the social contract of majority rule, and even if society is not perfect, at least it is not tyrannical, for it prevents the desires of the one becoming subsumed to the desires of the many. The sovereign administrates, but does not rule supreme for all time, if he violates his compact with the citizens.
Spinoza, Rousseau, and Sartre contrast one another in their approach to human rationalism, their embrace of human free will, and finally, in their confidence in science.
Of the three, Spinoza emerges as the philosopher with the greatest confidence in science, and the least secure believe in human free will. Spinoza's stress upon science and geometry in particular caused him to see human intellectual abilities as separate from physical institutions and influences. His rationalistic belief in the subjugation of human beings to larger forces led him to such a determinism, and the belief that the "body cannot motivate the mind," nor vice versa, shows a belief in a lack of control of both.
Rousseau believed in preexisting notions of human cognitive and social faculties, showing that he was not a radical empiricist -- the notion of a "Social Contract" between human and sovereign was not an observable thing, like David Hume might demand, rather it was founded upon assumptions about the human character. (498) But rather than concern himself about the nature of the mind, Rousseau was concerned in the declination of his philosophy with how humans behave in society, and function in a free society, without a sovereign, in the so-called state of nature. Humans are naturally acquisitive and rational in economic as well as philosophical terms in Rousseau's vision, and must recognize that it is empirically and scientifically in their interests to form by their own free will a binding social contract that can be dissolved if the sovereign violates their liberties.
Sartre believed that all human beings existed in a radical state of freedom. There is no "factual state" of an "economic society," as suggested by Rousseau. (230) Constructions of state and nationality are created by humans to deny the frightening truth that they are not bound, except by their own decisions, to obey such laws. Thus, the rationalism of Descartes that focuses on the division of physical and mental is completely undone by Sartre -- the very notion of scientific objectivity is nonexistent, for humans generate science in their own minds and modalities, for their own reasons. So to do they create notions of contracts, and the very concept of society and the will in general. "Absolute responsibility" and resignation to this fate is what is ethically demanded of human beings, rather than subjugation to the will of religious, state, or even scientific authority. (232)
It may seem as if these three philosophers are fundamentally different 'animals' in terms of their approaches to human freedom, social organization, and the issues of responsibility for human ethical actions of mind and body. But all three philosophers were dealing with different questions, and different responsibilities accorded to philosophy in their respective times. For Spinoza, the central query was between empiricism and rationalism, and if the human will in its abstraction was free or not. Philosophy was of mathematical and scientific importance, and theologically significant in terms of how it connected mind to body. Although Spinoza makes reference to the governing body of the king and responsibilities of the country, he proceeds always from one's theological obligations in the world -- one is obligated to be silent, as a moral duty, even though silence cannot enact societal change. However, Spinoza does not invoke silence amongst the polity as a political good, as might, for instance, Hobbes, whom Rousseau was reacting against.
Rousseau however was primarily interested in the human social body,…