Rationalism

The Basic Idea

Texting and driving. Virtually everybody who has a driver’s license can admit they’ve done it, despite knowing how dangerous it is.

And despite the millions spent on distracted driving campaigns, erecting billboards and increasing law enforcement on the roads, we still do it. Why? Because employing rationality isn’t always easy, especially when temptation exists around us.

In an era of contention and opposing headlines, using rationality can be a kind of opinion hygiene, a means of shedding misjudgments and motivated reasonings. In a time of partisan divide and views that tend toward the extreme, it promises to make sense of what’s grounded in fact and what isn’t. When the world changes quickly, we need strategies for understanding it. Using rationality is vital to that understanding.1

Rationalism reflects a reliance on reason—the philosophical idea that the fundamental starting point for all knowledge is not found in the senses or in experience, but instead can be traced back to some innate knowledge that we’re born with.2 This ‘original knowledge’ creates first principles, and the Rationalist epistemological school of thought purports that anything that can be logically deducted from those first principles is how we build our knowledge. 

Theory, meet practice

TDL is an applied research consultancy. In our work, we leverage the insights of diverse fields—from psychology and economics to machine learning and behavioral data science—to sculpt targeted solutions to nuanced problems.

Our consulting services

Key Terms

Innate Knowledge Thesis: Asserts that we have a priori knowledge, independent of experience gained through the senses, as part of our rational nature. Whereas experience can help trigger awareness of this innate knowledge, it doesn’t create it.3

Unreliability of Sense Perception: A Descartian distrust of sensory perceptions— the idea that the way we perceive sensory stimuli can be fallible, and therefore knowledge can only arise from the application of pure reason.4

Principle of Sufficient Reason: A fundamental tenet of rationalism, the PSR is a philosophical principle that contends that everything must possess a reason, cause or ground; there is nothing without an explanation and every event comes with a cause. 5

Empiricism: An approach to observing behavior through direct observation or experience. Empiricist theory is based on the claim that the main source of knowledge acquisition is experience, as opposed to the Rationalist claim that reason is the foundation of knowledge.6

Cogito Ergo Sum: A Latin phrase coined by philosopher Rene Descartes which translates to “I think, therefore I am” or more simply put, “I am thinking, therefore I exist”. This proposition became the cornerstone of Rationalist thought and exemplifies the existence of a thinking mind; the very act of doubting one’s own existence, Descartes suggested, serves as proof of the existence of an ‘I’ to do the thinking.7

People

René Descartes

A French philosopher and renowned rationalist thinker, well-regarded as the father of modern philosophy. Descartes alleged that knowledge is derived from conceptions of the intellect, not from the senses. He is credited with formulating the theory that knowledge and certainty in science can be attained solely by means of reasoning.8 

Wilhelm Leibniz

A fellow founding father of Rationalism and German philosopher best known for his contributions to the Innate Knowledge Thesis. Leibniz fervently believed that there was a rational order to our world, one that is graspable by the human mind. The PSR features as a fundamental axiom in Leibniz’s philosophy as a guarantor of the inherent intelligibility of the world.9

Immanuel Kant

A German academic in the 19th century and one of the most prominent names in modern philosophy. In his conception of epistemological rationalism, Kant suggested that the human levies its own inherent categories or forms upon experience, synthesizing the empiricist and rationalist schools of thought.10

History

Along with Empiricism, which stresses the use of sense perception rather than pure reason, Rationalism was one of the primary streams of intellectual thought during the Enlightenment period— a cultural movement spanning the seventeenth and eighteenth centuries. A focal debate of the Enlightenment was its controversy around the power of reason; most philosophers at the time praised the power of reason, but argued that the source of knowledge must be sensory experience.11

Rene Descartes’ ideology challenged this proposition; he argued that the knowledge of eternal truths could actually be attained by reason alone, without the need for any sensory experience. His famed proclamation of existence—“I think, therefore I am”— defines this very reasoning; it is a conclusion reached by reasoning alone and not inferred through experience.12

The rationalist position was that knowledge is a priori (‘from earlier’ – something you already have when you think about it). It is something that is reasoned out, for example, through the processes of mathematics or logic. The human mind is equipped with rational faculties, and if we utilize them, we can reach the truth. Reason, operating within the laws of logic, can attain knowledge of truths that owe nothing to sense experience.13

Descartes’ methodology was later adopted by Wilhelm Leibniz and Benedict Espinoza, two important figures in the development of Rationalist thought. Both agreed that the framework of knowledge could be known by a priori thinking. But the difference was their point of origin: Spinoza’s point of origin was not the self, but with that of the universe or God which he named Substance—an independent entity that needs nothing else to be conceived or exist. From the idea of Substance, Spinoza derived his entire system, contending that all aspects of the natural world and humanity were modes of this eternal Substance, and can therefore only be known through pure reason.14

Meanwhile, Leibniz expanded on the idea that principles can be accessed by reason alone with his idea of innate knowledge. He proposed that something like mathematical truths are not revealed by the senses, but rather, it is reason that allows us to procure universal truths from individual instances. Therefore, the mind is the source, which means such truths exist innately.15

While Descartes, Spinoza, and Leibniz are championed as the groundwork-layers of the 18th-century Enlightenment, Immanuel Kant, another prominent Rationalist thinker, came into the foreground during this period of intellectual excellence. Kant emerged to synthesize the relationships between human experience and reason, and attempted to put an end to an era of speculative theories of human experience. He did so by pointing out the flaws in both the Empiricist and Rationalist schools of thought.

Kant argued there were deep-seated problems with Rationalism. Pure reason, asserted Kant, is flawed when it goes beyond its limits and makes assertions on things that are beyond the realm of all possible experience—things like the existence of God, or the idea of free will. Regarding empiricism, Kant affirmed the necessity of experience for human knowledge, but suggested that reason is equally necessary for processing that experience into coherent thought. He concluded that both reason and experience are necessary for human knowledge, and called his framework Transcendental Idealism.16 

Consequences

In modern psychology, Rationalist thought has been routinely applied to the development of moral reasoning. A central question of moral psychology is that of how we make moral judgements. The rationalist account for this question is that we make such judgements consciously and deliberately through the application of explicit moral principles which we derive from some preexisting moral compass.17

Applying rationalist thought to our everyday lives can be hugely beneficial for our mental wellbeing and success. Especially in the context of decision-making, it is easy to let emotions cloud our judgement. This is why when we talk to others about our problems, they seem to come to a clear conclusion fairly quickly, as they are emotionally detached.18 

To effectively use rationalist thought, it is important to acknowledge and separate our emotions, instead applying our logical faculties to a given problem to elicit a more thoughtful and productive response. By making a conscious effort to refine our reasoning, considering the costs and benefits of our decisions, we can make better choices.18

Controversies

In psychology, Rationalism lies in opposition to several theories of perception; it counters the idea within genetic psychology that the categories of the mind develop only through the infant’s experience in concourse with the world. In a religious context, Descartes would say that we don’t learn to know God as a function of being brought up with religion, but rather we are born with some knowledge of God as a product of innate faculties of faith.19

Similarly, rationalism is opposed to transactionalism, a point of view in psychology that theorizes that the way we acquire perceptual skills is related to social exchange and human intractability. As kids we’re told to say our please and thank you’s; with time and repeated interaction we learn a core skill in practicing courtesy. Rationalism, instead, suggests that certain perceptual and conceptual capacities are innate rather than learned, and experience merely brings these capacities to light. 20

Emotivism, a branch of subjectivism in philosophy, also takes issue with rationalist explanations. An Emotivist account of moral judgement making suggests that moral disagreements are emotionally expressive, neither true nor false, and are therefore incapable of being resolved by rational discourse. For instance, an Emotivist would argue that the statement ‘I believe capital punishment is wrong’ is conisdered exclusively an expression of emotion, one which cannot be reasoned as correct or incorrect. 21

The emotivist school of thought has been on the rise due to significant experimental findings on moral judgment formation. Such work has demonstrated the importance of emotional processes in moral judgment. One study showed that impairment of the ventromedial prefrontal cortex—an emotion generating region of the brain—produces systematic variations in the way an individual constructs moral judgments.22

Case Study

A 2009 study conducted by researchers Kees van den Bos and Marjolein Maas of Utrecht University explored how a rationalist mind-set can stimulate innocent victim-blaming; for individuals who hold so-called ‘just-world beliefs’ (people get what they deserve and society is fair), being presented with innocent victims to a crime creates inconsistencies in their belief system. By employing rationalism, such individuals fall prey to victim-blaming to reconcile these inconsistencies.23

Mass and van den Bos expand on previous literature that suggests that individuals employ two information processing systems, experiential and rational, the latter of which operates through one’s logical rules of inference. The rationalist system is deliberate and thoughtful–while the experiential is automatic and rapid– and involves weighing information considerately. To test how this system affects victim-blaming attitudes, the researchers induced both experiential and rationalist mindsets unto their participants.

In the rationalist processing system portion of the experiment, participants were asked to respond to a given story founded on careful and analytic consideration of the information provided. Once induced with this mindset, participants were then introduced to a victim of sexual assault or robbery and were assessed to evaluate the extent to which they blamed the victim.24

The study revealed that individuals possessing rationalistic mind-sets tend to blame innocent victims more when they have a ‘just-world’ belief system than not. At the same time, those exhibiting an experiential mindset didn’t demonstrate strong effects of  ‘just-world’ thinking on victim blaming. The research suggests that the way we rationalize inconsistencies, especially when holding perhaps more idealistic views of the world (like the notion that bad things only happen to bad people), can encourage unfair biases. Moreover, it might perhaps remind us to mind jumping to conclusions when faced with threats to our preexisting belief systems.25

Related TDL Content

Does Emotion Affect Our Ability To Make Rational Decisions?

As psychology has evolved, so has our understanding of the role emotions play in decision-making; after all, humans are not robots defined by purely rational judgement making. This article explores how emotions play into level-two decision making—consumption decisions—and our conceptions of fairness.

To Be Right or Liked? Evaluating Political Decision-Making

Sometimes motivated reasoning and automatic, heuristic thinking can deter our efforts at reasoning rationally. This piece explores these kinds of biases in decision-making and sheds light on their effect in political attitudes.

Sources

  1. Rothman, J. (2021, August 16). Why is it so hard to be rational? The New Yorker. https://www.newyorker.com/magazine/2021/08/23/why-is-it-so-hard-to-be-rational
  2. Sangeetha, K. S. (2021, August 16). Sources of knowledge: Rationalism, empiricism, and the Kantian synthesis – Introduction to philosophy: Epistemology. https://press.rebus.community/intro-to-phil-epistemology/chapter/sources-of-knowledge-rationalism-empiricism-and-the-kantian-synthesis/
  3. Markie, P., & Folescu, M. (2021, September 2). Rationalism vs. Empiricism. The Stanford Encyclopedia of Philosophy
  4. Thilly, F. (1913). Romanticism and Rationalism. The Philosophical Review, 22(2), 107-132.
  5. Look, B. C. (2010). Grounding the Principle of Sufficient Reason: Leibnizian Rationalism and the Humean Challenge. In The Rationalists: Between Tradition and Innovation (pp. 201-219). Springer, Dordrecht.
  6. Difference between rationalism and empiricism. (2016, August 1). Pediaa.Com. https://pediaa.com/difference-between-rationalism-and-empiricism/
  7. Maden, J. (2020, October). I think therefore I am: Descartes’ cogito ergo sum explained. Philosophy Break – Your Home for Learning about Philosophy | Philosophy Break. https://philosophybreak.com/articles/i-think-therefore-i-am-descartes-cogito-ergo-sum-explained/
  8. (2015). René Descartes: Sensory Representations. obo in Philosophy. doi: 10.1093/obo/9780195396577-0272
  9. Look, B. C. (2010). Grounding the Principle of Sufficient Reason: Leibnizian Rationalism and the Humean Challenge. In The Rationalists: Between Tradition and Innovation (pp. 201-219). Springer, Dordrecht.
  10. Kant, Immanuel: Metaphysics. (n.d.). Internet Encyclopedia of Philosophy | An encyclopedia of philosophy articles written by professional philosophers. https://iep.utm.edu/kantmeta/
  11. Rationalism | History of western civilization II. (n.d.). Lumen Learning. https://courses.lumenlearning.com/suny-hccc-worldhistory2/chapter/rationalism/
  12. Rationalism – By movement / School – The basics of philosophy. (n.d.). The Basics of Philosophy: A huge subject broken down into manageable chunks. https://www.philosophybasics.com/movements_rationalism.html
  13. Darby, D. (2016, July 6). A brief history of philosophy, Part 8: Empiricism vs. rationalism. Lowimpact.org. https://www.lowimpact.org/brief-history-philosophy-part-8-empiricism-vs-rationalism/
  14. Spinoza, Benedict de: Metaphysics. (n.d.). Internet Encyclopedia of Philosophy | An encyclopedia of philosophy articles written by professional philosophers. https://iep.utm.edu/spinoz-m/
  15. Sangeetha, K. S. (2021, August 16). Sources of knowledge: Rationalism, empiricism, and the Kantian synthesis – Introduction to philosophy: Epistemology. https://press.rebus.community/intro-to-phil-epistemology/chapter/sources-of-knowledge-rationalism-empiricism-and-the-kantian-synthesis/
  16. Rationalism. (n.d.). Boundless. https://kolibri.teacherinabox.org.au/modules/en-boundless/www.boundless.com/world-history/textbooks/boundless-world-history-i-ancient-civilizations-enlightenment-textbook/the-age-of-enlightenment-458/the-enlightenment-1085/rationalism-1087-17679/index.html
  17. Clarke, S. (2008). SIM and the city: Rationalism in psychology and philosophy and Haidt’s account of moral judgment. Philosophical Psychology21(6), 799.
  18. Moore, D. (2016, February 16). Want to become more rational in your daily life? Try this CFAR rationality habit checklist. Clearer Thinking. https://www.clearerthinking.org/post/2016/02/16/want-to-become-more-rational-in-your-daily-life-try-this-cfar-rationality-habit-checklist
  19. Schmaltz, T. M. (2002). Radical Cartesianism: The French Reception of Descartes. Cambridge University Press.
  20. Blanshard, B. (n.d). rationalism. Encyclopedia Britannica. https://www.britannica.com/topic/rationalism
  21. Messerly, J. (2016, November 26). Emotivism. Reason and Meaning. https://reasonandmeaning.com/2016/11/26/emotivism/
  22. Koenigs, M., Young, L., Adolphs, R., Tranel, D., Cushman, F., Hauser, M., & Damasio, A. (2007). Damage to the prefrontal cortex increases utilitarian moral judgements. Nature, 446(7138), 908-911.
  23. Van den Bos, K., & Maas, M. (2009). On the psychology of the belief in a just world: Exploring experiential and rationalistic paths to victim blaming. Personality and Social Psychology Bulletin35(12), 1567
  24. Van den Bos, K., & Maas, M. (2009). On the psychology of the belief in a just world: Exploring experiential and rationalistic paths to victim blaming. Personality and Social Psychology Bulletin35(12), 1569
  25. Van den Bos, K., & Maas, M. (2009). On the psychology of the belief in a just world: Exploring experiential and rationalistic paths to victim blaming. Personality and Social Psychology Bulletin35(12), 1577

Read Next

Notes illustration

Eager to learn about how behavioral science can help your organization?