Image: V Panteon Stock photo ID:1844676677

In the 17^th century, Rene Descartes (d. 1650 A.D.) published several works of philosophy that had a substantial effect on how people in Europe thought about our world, and importantly, about our capacity to understand it. Since the great thinkers of ancient Athens, people sought to understand our world from the belief that everything, living and non-living, is comprised of form and matter. In non-living things, the analysis is quite direct: inspecting what a thing is made of gives you the matter of its being, and the shape tells you what it does. Taken together, the form and matter of something tells you what it is. In living things, understanding them is more complicated, and interesting. The “form” of a living thing is its nature which is shared in common by individual members of each species. Thus, for example, there is a horse nature, a dog nature, a human nature, and each member of a species expresses the nature of its species. This process of expressing a living thing’s nature begins at conception when the internal power of a thing’s nature shapes the body through gestation into a form that expresses the animal’s nature. Aristotle (d. 322 B.C.) gives a fascinating account of how the human soul in gestation produces a body that is the perfect instrument for expressing intellect. Descartes argued that the form/matter distinction does not tell us about things with any kind of certainty because our senses can deceive us. 

Greg Brown. Stock photo ID:878626144

Descartes also contended that appeal to final ends in things tells us nothing useful about them. This is a crucial element in the turn from pre-modern to modern thought. The issue here had to do with a general frustration over the fact that the study of being as an exercise in philosophy had not yielded the kind of certainty in our knowledge of things that many people wanted. Final ends, importantly explained for us in the writings of Aristotle, tell us what is thing is for. The final end of a thing is what it exists to do. Something or someone is a composite of form and matter, but the coming together of form and matter is done for a purpose, and understanding the purpose, for each kind of thing, gives us a complete understanding of what it is and its place in the order of nature. Final ends, however, suggest a giver of ends, that is, a creator who made everything, including us, with a purpose in mind. The idea that Descartes and others in his time were developing is that they might gain the kind of certainty of knowledge they desired of things if they examined things only from a materialist perspective.

Descartes proposed a method for studying the world and the things in it by starting from doubt. I will doubt everything, Descartes declared, that I cannot explain “clearly and distinctly.” So, Descartes begins considering things from the starting place of doubt, looking for what cannot be doubted, by observing that he knows he exists, as a thinking thing, because he is thinking. (This is the famous cogito ergo sum, I think, therefore I am. But Descartes was scooped more than a millennium earlier by St. Augustine who wrote that when he has doubts about God, he knows for certain that he himself exists because he is doubting. It may not be a co-incidence that Descartes had studied the writings of Augustine.) There is an important theme here that may not be obvious at first observation, and that is the search for a method of studying the world around us that uses the data of sense perception but does not rely on them. The senses can mislead us. St. Augustine understood this, too, and responded by observing that sense perceptions do not come to us already interpreted. We must take judgements of the mind about our sense perceptions and in this way work out the various ways that perceptions, at first, can be confusing. So then, can we trust our senses, or must we “trust the science”? 
READ MORE