Rationalism In Immanuel Kant's Epistemology

Immanuel Kant’s Epistemology

Eighteenth Century Europe was in turmoil, “characterized by dramatic revolutions in science, philosophy, society and politics” (Bristow, 2011, para. 1). Revolution was afoot in France, while earlier scientific discoveries from Copernicus to Newton drastically changed how humans understood the world. Empiricism and Skepticism rose with modern science to challenge the prevailing Rationalism (Murphy, 2010).

The grand and complex debate that emerged between Continental Rationalists, the likes of Renee Descartes and Gottfried Wilhelm von Leibniz, and British Empiricists, such as John Locke and David Hume, epistemologically hinged on the notion of whether there is knowledge beyond experience. More specifically, the debate

revolved around whether one could have knowledge beyond empirical experience, and therefore how much one can know with certainty (Markie, 2015).
At this juncture it is significant to distinguish between the types of knowledge. Knowledge that is a priori is “objective” and based on pure reason, with “all truths necessary truths that cannot be false” (Seung, 2007). The long-standing Rationalist belief held that knowledge is a priori, sourced from beyond direct experience, from what can be described as reason, logic. In essence, “theoretical, conjecture, or belief” (Seung, 2007, pp. 3). Empiricists, on the other hand, significantly influenced by the rise of modern science, maintained that knowledge can result only from direct empirical experience, or sense experience as it is often referred to, and is thus a posteriori, as in empirical or “known to be validated” (Dudley, 2011, pp. 19). “Reason may inform the relationship of ideas,” according to Empiricists, but it cannot generate knowledge (cite). Whereas Rationalists maintained all truths are knowable, Empiricists conversely held it impossible to have absolute certainty what is true (Dudley, 2011).
This is, admittedly, a simplification of the debate as it stood in the 1700’s. As it happens, philosophers have often accepted and rejected bits and pieces of their own and opposing philosophies, making it inaccurate to suggest a strict dividing line could be drawn between the camps. Nevertheless, these are the core concepts behind the Rationalist – Empiricist debate as encountered by Immanuel Kant (1724-1804), a well-respected professor and Rationalist in the Liebnezian tradition, who by account lived a happy and successful existence in Konigsberg, Prussia (cite).
In 1770, already in his forties, Kant took a position as professor of philosophy at the University of Konigsberg (Jankowiak, 1. Life, para. 2), up until this time, “fully enmeshed in the German rationalist tradition” (Jankowiak, a. pre-critical phase, para. 1) shaped by Gottfried Leibniz and Wolff. Kant was concerned over the growing sense that “everything can be explained in terms of science and mechanical laws” (podcast?), which threatened his belief in that which is beyond knowable, for Kant this chiefly faith and free will (cite podcast). It was in this atmosphere of uncertainty that Kant encountered the writings of Empiricist David Hume.
Hume’s theory of knowledge posits all knowledge is either analytic a priori or synthetic a posteriori (Stearns, 2013). For Hume, analytic a priori knowledge is “independent or experience” or simply “mere thinking” (Stearns, 2013). Analytic a priori truths are universal and necessary, or “true by definition” (Moore, 2008), for example all bachelors are single men or 2 + 2 = 4 (Stearns, 2013). The other prong of Hume’s Fork, as the theory is named, is synthetic a posteriori knowledge, which is derived from direct sense experience, or that which we would need to validate by empirical measures (Stearns, 2013; Moore, 2008). Rationalists and Empiricists agreed that knowledge exists as analytic a priori and synthetic a posteriori, but Hume asserted that all judgement is a posteriori to reinforce his view that “facts about that world cannot be known by reason alone” (cite). This directly challenged Kant, who until this point had “devoted himself to…reconciling the metaphysical claims of Rationalists with empirical science” (cite). For Kant, who believed “we can know things about the empirical world without basing this knowledge on experience” (Moore, 2008?), this comes too close to questioning the principles of the Enlightenment itself. Kant thus concludes “all analytic knowledge is a priori, but some synthetic knowledge cannot be a posteriori” (Moore, 2008), thereby creating a third prong for Hume’s Fork.
Analytic a priori knowledge can be described as true by definition or meaning, in that the subject is contained in the predicate, for example the previous statement “All bachelors are unmarried men” (cite). In Kant’s opinion, this could not translate to “7 + 5 = 12” (Dudley) or “between two points you can only have one straight line” (Moore, 2008), neither of which are “known by definition...[nor] require direct experience” to be known (Moore, 2008).
With Kant’s proposition of synthetic a priori knowledge, that which is based on pure reason alone, his pre-critical stage comes to a close as he rejects his own Rationalism and Hume’s phenomenalism.

With the idea of synthetic a priori knowledge as the springboard, Kant develops his critical philosophy, rejecting his own direct realism as well as Hume’s more radical Empiricist views (Seung, 2011). The Critique of Pure Reason (1778) is Kant’s seminal epistemological work, in which he outlines his “grand theory of perception,” which he termed transcendental (Seung, 2011, pp. 1). Kant’s transcendental philosophy provided a new way of understanding knowledge, and expanded our ideas of what we can know, how we know, and the limits to what we can

know.
Seung (2011) summarizes Kant’s theory of knowledge by identifying knowledge as that which “requires intellect in addition to sensibility” (pp. 3). Intellect provides us concepts, or thoughts, while sensibility provides awareness or intuition, and together these form a judgement, the “basic unit of knowledge” (Seung, 2011, pp. 3). Judgements can be a prior or a posteriori, analytic or synthetic, but only together can concepts and sensibility combine to result in knowledge (Seung, 2011, pp. 3). Kant believed our ideas begin with empirical a posteriori perception but evolve into intuitive a priori knowledge (Seung, 2011).
In the Critique of Pure Reason (1778) Kant strove to give structure to knowledge-making in arguing some truths are known only through pure reason, in the process giving rise to what we now refer to as human cognition.

In Kant’s view, human cognition or intellect, is comprised of sensibility and understanding. For Kant, sense perception is either a priori or a posteriori, the former being innate and intuitive, framed by space and time not in the physical but perceptual sense, while the latter is direct sense perception and empirical in nature (Seung, 2011). Understanding, in Kant’s philosophy, utilizes categories to structure and order thought in knowledge-making. According to Heidemann (2011) “categories are simply logical functions of judgements, but determinations of [a priori] intuitions” (pp.

54).
Kant explains reality in terms of phenomena and noumena (Seung, 2011). The phenomenal world is the knowable world, the synthetic a priori realm through which we can know reality as pure concepts (e.g. science, math, things). Conversely, the noumenal world is that which is “inaccessible or unknowable” (Seung, 2011, pp. 22). Here Kant set definite limits to what we can know, which is not everything. One of Kant’s most significant moves was to reclassify metaphysical knowledge as transcendental, effectively making it synthetic a priori and within the phenomenal, knowable world.
Equally groundbreaking was Kant’s perception of reality itself. The common perception in the Eighteenth Century was that the mind imposed reality on the world, meaning each individual’s reality might be different. Kant flipped this idea, asserting that “reality conforms to the structures of the mind, rather than the other way around” (Moore, 2008). To Kant, we all experience the same reality; we simply perceive our reality individually. This reversal in thinking, not unlike that of Copernicus with our universe, was dubbed Kant’s Copernican Revolution (cite).
In Kant’s view, reality is simply our perception of what we know to be true, but it is impossible to know the true nature of the world (Moore, 2008). Kant uses the metaphor of spectacles to illustrate his idea of perception. Time and space, for example, are the temporal-spatial lens through which we perceive and make sense of our innate sense perceptions (cite). Kant called his theory of perception Transcendental Idealism.
Legacy/Implications/Applications
Kant would later write two additional critiques, focused more on moral, ethical, political, and aesthetic theories, while the Critique of Pure Reason remains his greatest contribution to epistemic thought. Kant’s transcendental philosophy effectively brought an end to Continental Rationalism on the basis of synthetic a priori knowledge upset and effectively brought an end to Continental Rationalism. Rise of German Idealism. Established metaphysics as a legitimate discipline. Copernican Revolution’s as foundational for the advancement of scientific knowledge. Influence on the philosophy of math, physics, and science. Cognitive science. Longevity of transcendental idealism. Rise of theoretical science, through Darwin’s Origin of the Species, Einstein’s Theory of Relativity, and quantum mechanics, all theoretical in nature and unknowable by pure logic, discredited a prior knowledge from possibility, though the debate continues between today’s rationalists and empiricists. Even more so than in Kant’s time, one could find their philosophy rational in the realm of mathematics and empirical in the realm of the hard sciences.
When Kant died in 1804 he did not receive the understated funeral of his request, but a state funeral fit for a dignitary (Schaub, 1924). Even in his own era Kant’s contributions to philosophical thought were well recognized. Although some may have been disqualified over the intervening 211 years, his transcendental philosophy continues to be the focus of scholarly research, actively debated, and applied in the modern context, marking his timeless contributions to epistemology.