The core period of the Enlightenment, or Age of Enlightenment as it is often described, was the second half of the 18th century. However, the foundations were laid by the philosophers of the 16th and 17th centuries, whose works Jefferson was familiar with and espoused. Taken in the context of his notes on Religion, this quotation shows him to be a true Enlightenment thinker. The main aspects of that era reflected here are reason, experimentation, a belief in science, the freedom to inquire into everything, thus acquiring knowledge and enabling man to progress and to make his own decisions. He put forward the belief that government and legal coercion can only prevent the discovery of truth, and can actually encourage errors by supporting them, allowing them to continue, to the detriment of all learning and society. It might be said that governments support errors, while the truth supports itself.

His opening sentence raised the issue of how ridiculous the laws in France were, with regard to diet and medicine, removing the right of the individual to look after their body as they deemed fit. When he continued into the realms of science, philosophy and experimentation, his comments on Galileo, by the way in which they are phrased, tell us of his great admiration for the man and his work. At the same time, his brilliant use of irony, which indicts the government in question, suggests that it was attempting to legislate against the mind. Free thinking, new ideas, overturning of orthodox beliefs, all should be encouraged rather than punished. Jefferson ridiculed the same government in the case of Galileo for their reaction against reason, scientific experimentation, and the quest for knowledge. His tongue-in-cheek phrase:

‘This error however at length prevailed, the earth became a globe.’ (Jefferson, Chap. 17 1785)

tells us just what he thought of such rulers. Jefferson considered Frances Bacon, John Locke and Isaac Newton to be:

“three of the greatest men the world had ever produced” (Jefferson, letter to Benjamin Rush, 1811).

Their philosophies and actions are reflected throughout the quotation. Bacon had taken the work of Galileo and formalized it, suggesting that challenging orthodoxy and observing nature, using reason, would lead to true knowledge, with experimentation used to verify that knowledge. As a result, further theories would arise, with more experimentation to test their validity, and so it would go on. Jefferson is incorporating Bacon’s philosophies and methods, now described as Empiricism, into his comments on Galileo.

His treatment of Descartes was much less complimentary, though highly amusing in its imagery:

“Descartes declared it (the earth) was whirled round its axis by a vortex.” (Jefferson Chap. 17, 1785)

concluding with the hilarious idea of everyone being involved in vortices. He had to acknowledge that this time, the government did not make the mistake of forcing such a belief on the population.

It would seem that he rejected the Rationalism of Descartes’ philosophy, or rather, that element of it which excluded reference to the external world and contended that knowledge is gained by reason alone. Jefferson was a man of science and practical action, and while he accepted the ideas of critical questioning, was less impressed with the concept of thought without investigation or experimentation. The inference here may be that this particular founding-father of the Enlightenment did not wholly fit with Jefferson’s views, nor was he particularly impressed by all of Descartes’ theories.

The quotation also provides evidence of his admiration and commitment to the work and philosophy of Isaac Newton, with the inclusion of the theory of gravity and the fact that its power and truth was accepted and achieved through reason, not legislation. Here, he is telling the reader, is a seeker after the truth whose findings could not be overturned. Newton took the work of Gallileo and astrological studies of his time, worked out laws of motion and gravity (amongst much more), and presented incontrovertible truths. Scientific research, experimentation, defining Natural laws and sharing the knowledge, were all aspects of the man whose thinking Jefferson much admired. In the way he presents Newton, there is no doubt he is reflecting the Enlightenment thinking and values here.

A further connection lies in the links between Jefferson’s own religious beliefs and the upsurge of Natural Theology which resulted from Newton’s work. The idea that Nature is proof of the Divine, a Master Designer, appealed to Jefferson, who espoused one aspect of the theology, Scientific Deism. This contends that Nature was the result of Divine Creation, but then went on to operate as a result of universal laws, almost as if to say ‘Here is the product, now it will work without any further interference from Me (God).’ As a man of strong religious beliefs, yet a seeker after knowledge, a scientist, a thinker, Jefferson sees in Newton what Enlightenment means in practice. Despite his own firm religious beliefs, Jefferson is here advocating the idea that no form of coercion, no government intervention should stand in the way of knowledge, science, learning and the right of mankind to exercise individual conscience and beliefs. He is almost issuing a warning against such practices, saying, ‘look what happens when these rights are denied.’

In examining the quotation so far, it has portrayed elements of Enlightenment thinking around the philosophies of Empiricism (Galileo and Bacon), Rationalism, (Descartes) and Newton (Determinism). Where there is positive acceptance of all but Descartes, for reasons suggested earlier, the overall impression given suggests that Jefferson was reflecting more than rejecting the thinking and values of reason, experimentation, investigation, scientific proof and freedom of thought and conscience.

Although not mentioned overtly, the philosophy of John Locke is inherent here too. Locke’s theories on government greatly influenced political thought in Europe and the early United States. It is widely accepted that his political philosophies were a huge influence on both the Declaration of Independence and the American Constitution, and of course, Jefferson himself wrote that Declaration. Locke took Bacon’s empiricism a step further and contended that all knowledge is gained as a result of experience, man is a blank slate until he starts to use his five senses, reflects on the experiences internally, and so and begins to learn and develop. Thus it was environment which influenced an individual. In particular, Locke held that education and social institutions contributed to the development of a person’s beliefs, understanding and morality. Jefferson admired the practicality of Locke’s ideas, applying them to his own scientific activities. Locke’s philosophy, described as ’sensationism,’ i.e. what we know is based on our senses, links into Jefferson’s own love of gathering and recording factual information, using the senses to learn more about the world.

In the quotation, the need is expressed for facts, truths, as opposed to the ‘error’ of merely theorizing and speculating. That concept seems to be implicit throughout, bearing in mind that Locke advocated freedom of conscience and Jefferson is writing about religion and would appear to agree with him entirely.

In conclusion, the words used and the way in which they are used give a great deal of insight into the thinking of Thomas Jefferson and the values he held dear. There is no doubt his was an Enlightenment viewpoint. He treats those philosophers to which he connected and whose work he admired with seriousness and respect, citing them as good examples of his own beliefs. Those elements such as unreasonable laws, foolish governments and unscientific thinking, which he found unacceptable, he ridiculed with a fine ironic twist to his words. He was applying his Enlightenment values to the idea of freedom of conscience with regard to religion, the need for governments step back from coercion and thus compound error, and as he said:

‘Truth can stand by itself.’ (Jefferson Chap. 17, 1785)

References

Jefferson, Thomas 1767 Notes on the State of Virginia Chapter 17 Notes on Religion

Available from: http://xroads.virginia.edu/~HYPER/JEFFERSON/ch17.html

Jones, Roger, The Enlightenment

Available from: http://www.philosopher.org.uk/enl.htm

The Academy of Natural Sciences – Museum-Thomas Jefferson Fossil Collection

Product of the Enlightenment [internet]

Available from: http://www.acnatsci.org/museum/jefferson/otherPages/enlightenment.html