Psychotherapy as a Human Science

Truth, Method, and the Limits of Reason: Descartes and Pascal

24 Truth, Method,and the Limits of Reason Descartes and Pascal RENÉ DESCARTES René Descartes is commonly regarded as the founder of modern philosophy . He was born in La Haye, France, in the province of Tours in 1596, the youngest son of an eminent lawyer. He was a promising student and was sent to the Jesuit academy at La Fleche, where he studied literature, languages, philosophy, science, and mathematics. When he graduated at age 16, Descartes was baffled and dismayed by the startling diversity of opinions held by philosophers and doctors of the church on a wide range of subjects. But Descartes was less interested in discerning the real meaning of Scripture than in reconciling Scripture (and by implication, faith) with the findings of the newly emerging natural sciences championed by Galileo and others —a far more difficult task. Stranded at the intersection between faith and science, between medievalism and modernity, Descartes was obsessed with discovering the truth. But what is “truth”? For the sake of simplicity, let us define truth as parsimoniously as possible, as what actually is the case. But how do we discover what is (or is not) the case? Are there rules or procedures to follow? The oldest method for ascertaining the truth is Pythagorean in origin. Pythagoras said that rational introspection and the contemplation of mathematical formulas hold the key to the mysteries of the universe. He predicated the practice of rational introspection on the control and repression of the body’s senses and appetites, which he said led the soul astray. Pythagoras did not trust naturalistic observation to establish anything reliable or incontrovertibly true. The senses deceive, the passions confuse and mislead us. Reason — equated with mathematical reasoning — must somehow rise above the body, a task for which few are suited (Russell 1946). Plato agreed with Pythagoras, and by use of introspection claimed to discover innate ideas, which are accessible to rational introspection, which he likened to mathematical formulas, for example, proportion, justice, beauty, and truth. These forms, or ideas, are unchangeable and imperishable, and supposedly superior to the transient and corruptible evidence of the senses. Observable nature is thus, in a very important sense, less real than these quasi-mathematical forms he was talking about. Another way to ascertain the truth, said Plato, is the Socratic method, which attempts to elicit the truth in dialogue with others through a process of patient and prolonged questioning, in which the fundamental assumptions underlying various discussants’ ideas and assertions are gradually clarified, and their cogency or credibility examined critically, in light of other evidence and beliefs. In other words, the truth can sometimes be elicited or established intersubjectively, through rational discourse, provided we know how to ask the right questions and attest honestly to what we actually experience (Russell 1946). After the scathing dismissals of Pythagoras and Plato, naturalistic observation rebounded in the hands of Aristotle, who did not think that reason and sense perception were inalterably opposed. Unlike Plato, Aristotle credited patient and careful observation with supplying the intellect with the raw material it needs to infer the causal connections between various entities and processes in nature, leading us gradually to a rational intuition of the underlying structure of the cosmos (Clagget 1963). Thus, there are three ways of ascertaining the truth left to us by Greeks: (1) rational introspection, an intrasubjective process, (2) Socratic dialogue, an intersubjective process, and (3) naturalistic observation of the nonhuman world. To this venerable list the Hebrews added Descartes and Pascal 25 26 Truth, Method, and the Limits of Reason (4) the discovery of “revealed” truth through the careful and methodical exegesis of an authoritative text, an approach that spawned the modern discipline of hermeneutics (Ricoeur 1980). Another method for discovering truth was popularized by Francis Bacon, but only codified clearly and effectively by Descartes’s older contemporary, Galileo Galilei (1564–1642): (5) the experimental method. For Galileo and his followers , truth cannot be found in a book, or in the interiority of faith, or even in dialogue with friends or adversaries. These methods are quite fallible and as likely to mislead us as they are to inform. Truth is out there, so to speak, and its discovery depends on the proper coordination of patient, naturalistic observation, rigorous experimentation, and methodical theory building. Experiments enable us to quantify natural processes in controlled, artificial contexts that are designed for the purpose of...