Next, let us turn to rational reasoning. Rational reasoning concerns how something can be demonstrated in principle and derived through logic. Within Buddhism, there are three branches of learning that each provide a systematic process of reasoning.
The first is Buddhist epistemology and logic, or pramāṇa. Its basic mode of inference is that causes of the same type give rise to results of the same type. Broadly speaking, matter that lacks cognitive awareness can only produce matter, while mind endowed with awareness produces mind—this is the principle of “like causes giving rise to like results.” Matter that lacks awareness cannot suddenly give rise to a mind that possesses awareness; otherwise, the causal order of the world would become chaotic. It would be like gathering many blind people together and expecting sight to suddenly arise.
In fact, many modern scientists have expressed similar views. The renowned psychologist Carl Jung wrote in Modern Man in Search of a Soul: “The connection with the brain does not prove that the psyche is a mere epiphenomenon—causally dependent upon biochemical processes as a secondary function… The structure of the brain provides no explanation for psychic processes. The psyche possesses unique qualities that cannot be reduced to anything else.”
Professor John Eccles, a leading authority in modern neuroscience and a Nobel laureate in medicine, reached a similar conclusion after many years of experimental research. He stated: “Mind, or the self-conscious mind, is an entity that exists independently, just like the physical world. Although it resides in the brain and in some respects depends on it, its essential nature is not material.” To claim that mind is produced by the brain merely because there are correlations between brain activity and mental activity is, he argued, an arbitrary assertion. He also said, “This is a question that transcends science, and scientists should refrain from issuing definitive negative conclusions.”
To this day, scientists are still unable to answer the question of how matter gives rise to mind. For example, the famous quantum physicist Erwin Schrödinger, in his book What Is Life?, attempted to explain the essence of life using theories from thermodynamics and quantum mechanics. Yet when it came to the question of how mechanistic matter could produce a conscious subject endowed with free choice, control, and agency, he too fell into perplexity.
Many philosophers have likewise expressed similar views. The famous German philosopher Schopenhauer held that “death is the end of material life, but not the end of one’s existence.” Engels, a key representative of materialism, wrote in Dialectics of Nature: Life and Death: “Either the dissolution of the organism leaves nothing behind except the chemical constituents that made up its substance; or it leaves behind some vital principle, something more or less identical with what is called the soul. This principle survives not only the human being, but all living organisms.” What he expressed was also a stance of suspension of judgment, acknowledging that mental and material phenomena belong to two different categories.
In fact, the inferential reasoning of pramāṇa still retains a duality between matter and mind. Going a step further, Yogācāra philosophy in Buddhism negates the notion of matter through the reasoning known as “the six objects revolving around the central object,” and establishes the view that “all appearances arise from mind” through two lines of reasoning: the cognitively apprehended cause and the determining cause of co-arising conditions. If the world were composed of matter, then we would have to identify the smallest unit of matter. In science, this is called the smallest particle; in Buddhism, it is referred to as a subtle particle (paramāṇu).
About 2,500 years ago, Greek philosophers already proposed the concept of the “atom.” The atomists believed that when matter is divided repeatedly, it will eventually reach a point at which it can no longer be divided. The word “atom” comes from Greek and means “indivisible.” However, it was not until the eighteenth century that this idea was supported by extensive scientific experimentation. Subsequently, particles such as protons, neutrons, and electrons were discovered. Yet these are still not the smallest particles, and the scientific community continues to search for ever smaller ones. On the border between Switzerland and France, in the Jura Mountains, there is a Large Hadron Collider—the largest and highest-energy particle accelerator in the world today. Its main purpose is to study high-energy physics and fundamental questions such as the smallest particles, in an attempt to unravel the mysteries of the universe.
But what, fundamentally, is matter? To this day, science has not found the smallest particle. Einstein’s mass–energy equation shows that matter can be transformed into energy. But does energy itself have a material substance? Scientists are unable to answer this as well. String theory, proposed in the twentieth century, claims that the foundation of the world is strings, yet what these strings actually are, and whether they possess substance, remains unresolved. Thus, what matter ultimately is remains an open question even today.
Turning now to Yogācāra philosophy, its reasoning method known as “the six objects surrounding the central particle” is likewise an attempt to locate the smallest subtle particle. If it is truly the smallest particle, then it must be indivisible; if it could be divided into something smaller, then it would not be the smallest.
What does “indivisible” mean here? It means that this smallest particle cannot have six spatial directions—up, down, left, right, front, and back. If it did have such directions, then there would be separations between, for example, the top and the bottom, allowing it to be divided further, which would make it divisible after all. If this smallest particle has no up, down, left, right, front, or back, then it has no volume. Now, if one were to place one such smallest particle on each of its six sides, those six particles and the central particle would merge into a single entity, making it impossible to stack them into the material world that we perceive.
From this line of reasoning, Yogācāra negates the existence of matter: since no smallest particle can be found, matter is merely an illusion produced by the mind. It is like the world in a dream—the BMWs, computers, mountains, rivers, land, flowers, and grass that appear in a dream are not composed of matter; they are merely illusory appearances generated by the dreaming mind.
Furthermore, Yogācāra philosophy establishes the principle that “all phenomena are mind-only” through the reasoning of the “cognitively apprehended cause ” and the “determining cause of co-arising conditions.” Earlier, by using the reasoning of “the six objects surrounding the central particle,” we negated the idea that the world originates from matter. Then what does the world originate from, and how is this derived? Buddhist logic tells us that for a line of reasoning to be established as true, it must satisfy the criteria of “three-characteristic inference.” However, these topics are quite technical, so we can only discuss them in broad outline here.
Let us now look at the formulations of the “cognitively apprehended cause ” and the “simultaneous-conditions determining cause.”
The inferential formula of the “cognitively apprehended cause ” is as follows:
The apprehended external object (the subject) must be one entity with the consciousness that apprehends it (thesis), because the external object does not exist independently and is merely an appearance of cognitive awareness, possessing the defining characteristics of consciousness (reason).
The inferential formula of the “determining cause among co-arising conditions ” is as follows:
The perceived external object (the subject) is one entity with the consciousness that apprehends it, or at least not a different entity from it (thesis), because they arise through simultaneous conditions (reason).
When people first see these two formulations, they may feel completely puzzled. Every word is familiar, yet when put together, it seems incomprehensible. That’s fine—explained in plain language, it becomes clear. The meaning of the cognitively apprehended cause is this: the establishment of any thing necessarily depends on my cognitive awareness to establish it. If I am not aware of it, there is no way to say that a thing is established. Think carefully—everything you see, hear, feel, or think is inseparable from your cognitive awareness. Apart from your awareness, what can you actually confirm to exist? You might say, “I imagine something existing apart from my awareness.” But at that very moment, it is precisely your imagining that establishes its existence.
The meaning of the simultaneous-conditions determining cause is that the appearance of a thing and my knowing of it must occur at the same time. If it appeared earlier while I had not yet known it, then where exactly did it appear? Or if I had already known a thing while it had not yet appeared, that would be equally absurd. Therefore, the appearance of an object and my cognitive awareness of it must necessarily be simultaneous.
If you reflect carefully on these two lines of reasoning, you will find that they completely encompass all of your cognition, and that no counterexample can be found. From this, it is established that what you cognize, together with your cognition itself, is nothing other than mind—thus establishing the principle that “all phenomena are mind-only.” For example, the elephant that appears in your dream and the cognition of that elephant are both manifestations of your own mind.
Regarding these philosophical reflections, many people may not be able to fully grasp them right away—and that is perfectly fine. These theories are open and accessible; one is free to study, contemplate, and analyze them carefully to see whether they are correct and internally coherent. Buddhism is, in fact, highly scientific and systematic, and it requires time and study to truly understand it.
In summary, Yogācāra philosophy uses the reasoning of “the six objects surrounding the central particle” to negate the existence of matter, and employs the cognitively apprehended cause and the simultaneous-conditions determining cause to firmly establish mind-only. Since mind does not cease abruptly (it does not suddenly vanish), nor does it arise without cause, it can only flow from one moment to the next. Then where does the cause of the very first moment of consciousness in this life come from? It cannot be without a cause; it can only arise from the final moment of the previous life (or what is called the intermediate state). This is the general framework by which Yogācāra philosophy infers the existence of rebirth.
Next, how does Madhyamaka philosophy in Buddhism reason through this issue? In fact, from the ultimate standpoint of Buddhism, even samsara is not affirmed; samsara is merely an illusion, a dream-like delusion. Chan Master Yongjia said, “In the dream there are clearly the six realms; upon awakening, emptiness—there is no great cosmos at all.” Yogācāra says that all phenomena are mind-only, while Madhyamaka goes further to say that even mind itself cannot be found as an entity. When there is no entity, there is no birth and death—yet this does not mean that there is ‘nothing at all.’
Mind possesses the characteristic of cognitive awareness. When this knowing mind differentiates into a knowing subject and a known object, illusory appearances arise, the vast cosmos appears, and a dream-like samsara unfolds, one dream following another. Since we are still at the stage of “in the dream there are clearly the six realms,” how do we infer the provisional existence of samsara? Madhyamaka philosophy offers many methods of reasoning. Here we will briefly introduce one called the “neither-one-nor-many” argument, which shows that no real ‘one’ or ‘many’ can be found.
Is the world truly material? Take a wool sweater as an example: it is made of yarn; the yarn, in turn, is made of smaller particles. We keep tracing this back—atoms, atomic nuclei, quarks… but what exactly is the smallest particle? Scientists attempt to determine this through large particle accelerators, trying to split particles into ever smaller ones, in order to determine the smallest particle. The crucial question is: can such a smallest particle actually be found? If it still has volume, then it can be further divided and is therefore not the smallest. If it has no volume, then the very foundation of material existence collapses.
In fact, the line of thinking of modern scientists coincides with that of the philosopher Zhuangzi. Zhuangzi said, “Take a one-foot stick: halve it every day, and it will never be exhausted, even in ten thousand generations.” Roughly speaking, this means that if you take half of a one-foot stick today, then half of the remaining half tomorrow, and continue halving in this way, there will always be half left, endlessly. However, this is actually a mistaken view. If an object could be divided infinitely, then a one-foot stick would have to be composed of infinitely many smallest particles. Why? Because of the assumption of infinite divisibility. Such a ‘smallest particle’ would then be an infinitesimal. Those who have studied Buddhist logic know that an infinitesimal is merely a conceptual pointer—there is no such thing as an actual infinitesimal in lived reality.
Let me give another example to clarify this point. Suppose I use a needle to pierce an apple. First I pierce halfway through, then halfway through the remaining half, then halfway through that half, and so on. According to this reasoning, there should always be half remaining, and my needle would never pass through the apple. Yet in reality, the needle passes through the apple instantly. Reality delivers a sharp refutation of this reasoning. Moreover, if a one-foot stick were composed of infinitely divisible infinitesimal particles, then Mount Everest, at 8,848 meters high, would likewise be composed of infinitely many particles. But if both are made of infinitely many particles, why is there such a vast difference in volume? Thus, Zhuangzi’s reasoning contradicts reality and is incorrect: an object with finite volume cannot be divided infinitely.
As one continues dividing, reaching later and later stages, it becomes clear that the earlier stages were merely illusory appearances and cannot be ultimately obtained. When division is carried through to its end, one discovers that the foundation of material existence does not exist at all. The entire world then appears like a dream—matter is not the source of the world.
So what, then, is the source of the world? It can only be the mental, the mind. On the relative level, the law governing mind is that one moment gives rise to the next. Therefore, the first moment of consciousness in this life can only come from the previous life. Here we have only sketched, in the briefest outline, how Buddhist logic, Yogācāra, and Madhyamaka each infer the existence of saṃsāra . All of these inferences are established through rational reasoning.
This article is a preliminary translation draft and has not yet been reviewed or proofread by the speaker.
