To have certitude about the laws of nature and thereby establish philosophical foundation for science, it is essential to discuss whether it is possible for us to find causality (i.e. necessary as “cannot not be”) amongst the events of nature. I intend to go through the flow of the philosophical debate in the early modern times that centered on this topic to showcase what are thought to be conditions for finding causality. But, it is my argument that we cannot have certitude about the laws of nature (1) because Kant’s case for possibility of finding causality is i) insufficient as it only describes that there is causality, which is not much different from saying that there may be causality; ii) we cannot find initial/ultimate cause that is necessary to establish complete causality, (2) and because even if our science evolves along with the so-called “paradigm shift” of Thomas Kuhn, we are not capable of reaching the right paradigm.
To begin with, RenéDescartes, the father of modern rationalists, attempted to assert scientific certitude by radical (doubting all hitherto acquired knowledge) and systematic (reassessing all kinds of knowledge by tearing down and rebuilding) “doubt” as what is indubitable in any circumstance ought to be secure in its certainty. For Descartes, all knowledge that were derived by our senses were doubtful as senses were clearly deceiving (e.g. optical illusion). Thus, Descartes went far as to doubt his self, the thinking agent by questioning can the evil genius (a demon of utmost power and malice that uses all energy to deceive us) deceive him of his existence. The answer is no because if he did not exist, the evil genius cannot deceive him; you cannot deceive someone who is not there. This is the renowned claim cogito, ego sum (“I think, therefore I am”).
Such certainty regarding our existence, in terms of self-identity and be-ing, is subject to controversy though. Hume, for instance, raised an extremely skeptical voice for our actual self as he claims that we are mere “bundles of perceptions.” To elaborate, Hume sees our mind or ego not as independently unique but collection of repeating experiences, or perceptions at every moment. Our self is not of same identity throughout (my past self and future self are different from my present self).
Nonetheless, I want to make clear that it is not the ontological certainty of our self or be-ing that is at issue here, but it is whether our cognitive ability can possibly have certitude about the laws of nature that is at issue. Although it may seem at first glance that our self-identity or be-ing needs to be certain in order to perceive something with certainty (it is awkward to say that a being that cannot be sure of oneself can be sure of other things), I consider it as reasonable as how we, the imperfect beings, can know of or have faith in God, the perfect being.
Now, let us return to our main battlefield, in which whether our cognitive ability has the possibility to grasp certitude in nature is at issue. After establishing the thinking self with certainty, Descartes attempts to find what can be called certain in the contents of our cognition (i.e. from what we are thinking). Descartes maintains that any knowledge derived from the senses are shaky as senses are deceiving and ambiguous. For instance, the qualitative properties (relates to our senses) of cold and hot are hard to define in that it is ambiguous whether cold is absence of hot or hot is absence of cold. Such properties cannot be a positive property in a thing. Some may argue that the theoretically lowest possible temperature “absolute zero” can be a qualitative property that is definitive. But, I defend that absolute zero has not yet been empirically experienced anywhere, and that it can be a quantitative property instead that is based on the theoretical temperature/number of 0° on Kelvin scale.
Such is the reason why Descartes focuses on finding amongst our knowledge what can be “a condition for possibility of experience” (a priori) because knowledge that comes before experience can be derived without any experience, and hence can be called “innate” ideas. For Descartes, geometrical figures were as such since somehow we have the idea of a perfect triangle in our minds though we have never seen one in reality. The quantitative properties of length, breadth, depth, speed, vector, etc. are definite and can be used in analytical reasoning (mathematics) in explaining the causality of things: P à Q, which Descartes indeed does when suggesting a mechanistic mode for all natural sciences. Borrowing Leibniz’s view in addition, mathematics can render the world fully explainable by the format of A: B in terms of “1 + 1 = 2” (although for Leibniz, such high-level of computation is only capable by God).
In contrast, John Locke, the modern capital of empiricism, launches attack on Descartes’ rationalist foundation that there are innate ideas in our minds. Locke contends that if there are any a priori knowledge in our minds, it would be absurd for our mind to not be aware of it. But, it is apparent that children are not aware of such knowledge prior to experience. For Locke, we have formed the idea of a perfect triangle by experiencing many approximately triangular shapes in reality.
To illustrate Lock’s view of the mind, let us bring in Aristotle’s Tabula Rasa, i.e. our mind is a “blank slate” on which imprinting by experience is sine qua non to have ideas. Locke further demonstrates that the ideas we have are perceived by our synthetic judgment, i.e. our sensation (external sense) receives simple ideas and our reflection (inner sense) combines them into complex ideas. For instance, the idea of sound (auditory) or people talking (visual) does not make full sense if perceived alone. The two ideas need to be synthesized for us to have accurate perception. Thus, Locke maintains that all of our perceived knowledge in the mind is formed by synthetic judgment and is subsequent to experience, and hence a posteriori.
Therefore, in regards to how our mind acquires knowledge, the rationalist model is “deductive reasoning (e.g. all humans die à so, you will die too one day)” while the empiricist model is “inductive reasoning (e.g. everyone I know of died eventually à so, all humans die).” Both attempts to establish causality for finding necessity in the laws of nature.
Gottfried Wilhelm Leibniz, as a rationalist, deals a blow to knowledge gained by inductive reasoning by framing it as that of beasts. For instance, a turkey may induce through several months of experience that even on the Thanksgiving Day the farmer will come to feed it, rather than feed on it. Thus, inductive reasoning hardly entails certainty as it does not securely establishes causality. It is always accompanied by the perpetual risk of another outcome (e.g. we can never know if in the future there will be born a man that does not die).
Ironically, David Hume, as an empiricist, acknowledges Leibniz’s critique on inductive reasoning, thereby revealing his intention as a skeptic to target the possibility of our cognitive ability to find necessity in nature. On one hand, Hume demonstrates that inductive reasoning fails in finding causality as it mistakes “A precedes B” as equal to “A causes B,” which is easily not the case. Hume thereby bars certainty coming from a posteriori.
On the other hand, Hume demonstrates that even the analytical reasoning of mathematics: P à Q falls short in fully being applied to natural sciences when finding causality. If by deduction we want to prove that P à Q (=T) is true, we can prove that vT (opposite of T) is false. In other words, if opposite of T is impossible, then T is necessary (i.e. “cannot not be”). But, such necessity, which we hurry to call truth has to be distinguished from matter of fact. The former is when its contradictory is not conceivable (e.g. a square circle). The latter is when its contradictory is conceivable (e.g. a pushed billiard ball jumping over another billiard ball instead of colliding), and so not necessary. Likewise, we have a fallacious tendency to proceed from one known fact (e.g. “I see a watch on a shore of an island.”) to another unknown fact (e.g. “I infer that there was someone who came before me.”). Though such deductive inference from the known to unknown seems plausible, it does not establish any necessity between the two (it only establishes that if the premise is true then the conclusion is valid). Hume thereby bars certainty coming from a priori as well (for Hume, only mathematics per se can have necessity, and so certainty).
Such long-resisting deadlock between the two camps in attempt to find some sort of certainty in nature was seemingly completely resolved in his time by Immanuel Kant. The so-called transcendental philosophy of Kant investigates on the “condition” for our cognitive ability to know things with certainty. On one side of the coin, Kant adopts the empiricist view that our knowledge at firsthand must come from the senses. What goes beyond our senses are of antinomy, in which arguments such as “God exists” and “God does not exist” can both equally be accounted with reason, and so causes confusion to our reason (A wordplay on Hume that Hume is certain that he cannot be certain may also be a case of antimony). This is why Kant critiques against such usage of pure reason (when our understanding of things is applied to things beyond our senses).
On the other side of the coin, Kant adopts the rationalist view that there is indeed something innate within us, but it is not the content of our cognition but the system of our cognition that is so. Kant puts the common ground of the two camps (what is analytic is a priori and what is synthetic is a posteriori) to the test by proposing that what is synthetic is a priori, the so-called synthetic a priori judgment.
Up until then, it was almost blindly believed that the object is imprinted through senses on our synthetic cognition (object à synthetic cognition). However, Kant ingeniously proposes that our synthetic cognition, which is a priori, constructs what we observe to be the object (synthetic cognition à object). In other words, Kant is claiming that whatever we perceive are “things in the view of innate human cognition (things as seen in the light)” and not the “things in themselves (things in the dark).” For Kant, perceiving things in themselves is equal to the attempt to see things in the dark as they appear in darkness, which is practically impossible for us. Therefore, synthetic a priori judgment (the light) is what Kant proposes to be the condition for us to grasp certainty about the laws of nature.
Kant’s task to demonstrate our synthetic cognition as a priori involved attributing all properties and that were believed to be from the things in themselves and the world to our cognitive ability. For Kant, what is felt by our five senses has to go through two gates of our synthetic judgment, namely 1) sensibility and 2) understanding. The former, sensibility (passive faculty of receiving), refers to the condition that makes our sensual experience possible, and so it cannot be derived from the senses, and hence a priori. On one hand, Kant maintains that “space” is as such since it is a condition that makes possible our senses to be associated with objects that are outside me (even “shape/extension” what Descartes believed to be the residual property of things are actually due to us). On the other hand, Kant maintains that “time” is as such as well since it must precede experience to make succession or simultaneity of things appearing possible.
Nevertheless, Kant’s synthetic a priori judgment seems to give an impression of an anthropomorphic view. Not that Kant was prejudiced, but more like our cognitive ability that he describes only seems to show the world as it is shown to us, which does not entail any certainty about the laws of nature. It is under the categories of our understanding (active faculty of making judgment) that Kant proposes our possibility to establish causality in things, and thereby find necessity and certitude.
To articulate Kant’s thrust, let us restate Hume’s view for reminder that since all synthetic judgment comes from experience, it is impossible to establish causality. Kant notes that according to Hume, even mathematics cannot be science (on contrary to Hume’s recognition of mathematics per se as the only science) as mathematics is actually synthetic. Kant mentions that when demonstrating the isosceles triangle, it would not be enough to just look at it, waiting the figure to inform us of its properties. Instead, we must actively use logic to construct it, which is by synthetic a priori judgment. Kant, in other words, is saying that the categories of our understanding, despite being “human” cognitive function, are given to us for us to correctly understand the laws of nature (a different system of intelligent cognition may be out there, which may show the world in a different way, but the understanding of the laws of nature will probably not differ).
Kant applies the same line of reasoning to propose that we are capable of establishing causality in natural sciences as well. To give an example, Newton’s Law of Gravity is generally accepted as scientific truth and have been empirically proven to apply everywhere at least within the scope of our observation. It must be noted, however, that Newton’s discovery of the law was partially intuitional as he did not fully explained as to where exactly the gravity comes from. Yet, it is astonishing how it has not met any major discrepancies till today, which seemingly adds weight to Kant’s stance.
In my opinion, however, the causality we establish in natural science by Kant’s category of understanding (and as a whole by synthetic a priori judgment) is not complete, in terms that it does not sufficiently demonstrate necessity. We must note that Newton only described that there is causality with regards to gravity. Even in our contemporary era, in which science is almost piously revered of its accomplishments, it is only explained, or described in much more rigorous detail, that “two objects of heavy mass attract together.” It is not fully known as to how/why this phenomenon becomes the source of gravity.
According to the scientific community, the purpose of science is to 1) describe, 2) explain, 3) find the cause, and 4) and predict natural phenomenon or biological/psychological behavior. Precisely, what science truly aims is not just to describe that there is causality between A and B, but also to sufficiently explain how/why A causes B, and eventually be able to always predict B when A occurs, or control B by the manipulation of A. Despite so, it is not rarely testified by famous scientists through media that they have only come to “describe” the laws of nature. Thus, Kant’s a priori intuition of our synthetic cognition to find causality falls short in completely satisfying what science ought to truly achieve.
Kant’s fortress may be further subject to attack as establishing a complete causality requires reasoning on domains that goes beyond our experience. Specifically speaking, we can always ask what the cause of a cause is endlessly. Thus, unless we can find whether the initial/ultimate cause (which is not dependent of any cause to exist) is out there, we cannot say for sure that we can have any kind of certainty. On one hand, we can reason that an infinite series of causes is satisfactory. On the other hand, we can reason that God is the initial/ultimate cause. Note that this is a case of antimony, in which it is not within our ability to draw an answer.
Last but not least, Thomas Kuhn, an American physicist and philosopher of science introduced what is called a “paradigm (a standard frame of thought in particular era or area)” to demonstrate a worldview in which science simply changes its method of explaining (or “describing”) the universe as paradigm shifts (Kuhn does maintain though that the new is always better than the old). Unlike how science was believed to be a steady process of getting closer and closer to the truth (from vagueness to certainty), Kuhn claims that per each shift in paradigm (e.g. “Ptolemy’s geocentric model” shifting to “Copernicus’ heliocentric model”) a totally new and vague truth emerges along with development. Although it is argued that when we reach the right paradigm with no vagueness, there won’t be any shifts because we have achieved all true knowledge of nature. But, it is my belief as previously mentioned that we cannot reach this last paradigm. The role of science discussed by Kuhn resembles goggles that allow us to see better, and we are changing goggles (to technologically more advanced ones) but note that no matter how good a goggle is, it is us who are wearing that goggle to see what we ought to see. It appears to me that it is because of our cognitive limit in finding certainty that we are in the repeating cycles of paradigm shifts. In other words, we always need of “better” science because we cannot know of the “right” science.
In conclusion, the journey to search for our potential in attaining certitude about the laws of nature, as we can see, has bypassed the following flow:
 Rationalist (Descartes & Leibniz) view that there are innate ideas not based on judgment, and so we can find causality;
 Empiricist (Locke / Hume) view that our knowledge comes from sensory experience, and so we cannot find causality;
 Kant’s proposal of an innate system of our synthetic cognition that is given ability to find causality, which can be applied to natural science;
 My view that  does not completely establish causality, and so does not satisfy science, as it only describes there is causality;
 My view that we cannot completely establish causality because it requires initial/ultimate cause, which is beyond what we can practically account for;
 The fact that we are in the seemingly endless paradigm shift means that we cannot have certitude regarding the laws of nature.
Ariew, Roger, and Eric Watkins. “Descartes, Meditations on First Philosophy.” Modern Philosophy: an Anthology of Primary Sources, Hackett Pub. Co., 2009.
Ariew, Roger, and Eric Watkins. “Locke, Essay Concerning Human Understanding.” Modern Philosophy: an Anthology of Primary Sources, Hackett Pub. Co., 2009.
Ariew, Roger, and Eric Watkins. “Leibniz, New Essays, Preface.” Modern Philosophy: an Anthology of Primary Sources, Hackett Pub. Co., 2009.
Ariew, Roger, and Eric Watkins. “Hume, Treatise on Human Nature.” Modern Philosophy: an Anthology of Primary Sources, Hackett Pub. Co., 2009.
Ariew, Roger, and Eric Watkins. “Hume, An Enquiry Concerning Human Understanding.” Modern Philosophy: an Anthology of Primary Sources, Hackett Pub. Co., 2009.
Ariew, Roger, and Eric Watkins. “Kant, Critique of Pure Reason, abridged.” Modern Philosophy: an Anthology of Primary Sources, Hackett Pub. Co., 2009.
Kuhn, Thomas S. The Structure of Scientific Revolutions. The University of Chicago Press, 2015