The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Concept of Science in the Kālacakra Tradition
The Inner Kālacakratantra
A Buddhist Tantric View of the Individual
When the issue of science is raised within the context of Indian Buddhist thought, there are no more advanced or comprehensive matrices of theory and practice than those presented in the literature of the Kālacakra tradition. A textual study of the Indian literary sources of this tantric tradition reveals that when Brāhma ic for mal education in eleventh-century India was ṇ exclusively theological and disdainful of technical knowledge,  north Indian Buddhist monastic education incorporated training in nontheological skills that required knowledge of medicine, alchemy, mathematics, artisanship, and even weaponry.  The sharp split between theological and scientific education, which impaired the Brāhmaṇic educational system of that time, was absent in Buddhist monastic education due to the prevailing Buddhist view that theological knowledge and technical and scientific learning are not only compatible but complementary as well. 
The literature of the Kālacakra tradition with its diverse and well-integrated topics and applications of the diverse fields of knowledge best attests to that fact. The integration of diverse fields of knowledge by this tantric tradition has its roots in the Buddhist monastic, educational system. The study of the five fields of knowledge (pañca-vidyā)—linguistics, logic, inner science (metaphysics and philosophy), medicine, and creative arts—was incorporated in Buddhist education at the time of the emergence of the Mahāyāna Buddhist monastic universities. Mahāyāna monasteries were the first to offer educational opportunities to both the monastic and lay Buddhist communities; and they were the first to provide them with religious and secular education as well. This is very significant in light of the fact that in the Indian Buddhist world, educational opportunities did not exist apart from monasteries. In early Buddhism, Buddhist education was entirely monastic in its content and available only to those who entered or intended to enter the Buddhist monastic order. The origin of the Buddhist educational system was closely tied to the inception of the Buddhist monastic order. The Buddhist educational system actually arose from the need for instructing monastic novices. Each novice (śrāmaṇera) at his ordination (pravrajyā) was placed under two senior monks, one called a preceptor ([[upadhyāya) and the other a personal teacher (ācārya). From
the description given in the early Buddhist Pāli texts (Mahāvagga, Ch. 1. ), it seems that the upadhyāya was responsible for instructing the novice in Buddhist texts and doctrine, whereas the ācārya was responsible for training the novice in the proper conduct of a fully ordained monk. After the novitiate period was over, a novice aged twenty or older underwent a second ordination (upasampadā). As a fully ordained monk (bhikṣu), one received further training to become well versed in Buddhist scriptures and meditation. That period was called niśraya, or “dependence, ” and it could be reduced to five years or extended for a lifetime. Once that period was over, a trained monk was allowed to teach younger monks as an independent ācārya. Thus, in early Buddhism the unit of the Buddhist educational system was a young monk or a group of young monks living under the supervision of two elders who were responsible for their entire well-being. Many such groups of students and teachers resided together within a single monastic institution.
This pattern of collective life and organization of education carried over to the educational system of Mahāyāna Buddhism where it was further developed. However, unlike the Mahāyāna texts, the early Buddhist writings  refer to the creative arts, craftsmanship, scribing, and similar fields of knowledge as vulgar fields of knowledge (tiracchānavijjā), which are studied only by lay people. Likewise, in the early Buddhist period, the Buddhist laity had to seek other educational centers when they needed nonreligious education. With the advent of Mahāyāna, there was greater emphasis on promoting general education for the entire Buddhist community. There were two main reasons for that shift in the priorities. One reason was Mahāyāna's recognition of the Buddhist lay life as a viable way of life in the pursuit of spiritual awakening, and the other reason lay in the Bodhisattva ideal and the ideal of perfect enlightenment characterized by omniscience.
Therefore, whereas in early Buddhism attention was given almost exclusively to the elimination of spiritual ignorance, Mahāyāna Buddhism was concerned with the eradication of every kind of ignorance. As some Mahāyāna texts attest, a Bodhisattva was encouraged to gain proficiency in all kinds of knowledge in order to attain the six perfections and assist others in every way needed. The Bodhicaryāvatāra, for instance, declares, “there is nothing that the Children of the Jina should not learn. ”  In this regard, in the Mahāyāna Buddhist tradition, the study of the five fields of knowledge was considered necessary in both pursuits—the pursuit of one's pragmatic, mundane ends and the pursuit of spiritual awakening. It is said in the Mahāyānasūtrālaṃkāra: An Āa who does not undergo training in the five fields of knowledge in no way attains omniscience. He trains in them in order to defeat and assist others, and in order to gain knowledge for himself.  The text further explains that by studying linguistics and logic one is able to defeat opponents in debate; by studying medicine, the creative arts, and similar disciplines, one assists those who desire so; and by studying the inner science, or Buddhism proper, one gains knowledge for oneself. Likewise, mastery of the five fields of knowledge was considered as one of the characteristics of Buddhahood itself.
In the Vyākhyāyukti,  or the Sūtravyākyāyuktyupadeśa, Vasubandhu states that Buddha's teaching is called comprehensive because it demonstrates his proficiency in every field of knowledge. In tantric literature, specifically in the Vajrapañjaratantra, a good vajrācārya is said to be completely versed in all fields of knowledge. As I will try to demonstrate throughout this book, the Kālacakra tradition supports this view of the Buddha's omniscience as inclusive of all forms of learning, and it accordingly integrates the diverse branches of exoteric learning into its esoteric theories and practices. The fact that the entire Kālacakratantra can be divided into two main parts—one dealing with diverse disciplines pertaining to the theoretical knowledge of the world and the other pertaining to meditation—indicates that the Kālacakra tradition also agrees with the Mahāyāna view that one is unable to get the firm footing in Buddhist teachings and practice by study and analysis alone, without the practice of meditation, or with meditation alone, without study.
In this way, it concords with the earlier Maha flyāna view expressed by the following verse from the Mahāyānasūtrālamkāra: Meditation would be useless if reality could be perceived through mere study; and the teaching would be useless if one could practice meditation without having studied.  The topics of the Kālacakratantra's first two chapters—called respectively “The Universe” and “The Individual”—deal with the investigation of the universe as macrocosm and of the individual as its microcosm. The Kālacakratantra's inquiry into the nature of the external world and the individual as two facets of the phenomenal world—the external (bāhya) and internal (adhyātma)—utilizes knowledge of the various branches of Buddhist science. Disciplines analogous to cosmology, astronomy, astrometry, chronometry, embryology, physiology, psycho-physiology, anatomy, medical therapeutics, pharmacology, alchemy, botany, psychology, and philosophy are either directly or indirectly incorporated into the Kālacakratantra, especially into its first two chapters. For this tantric tradition, those diverse scientific disciplines provide a systematic analysis of the natural world, provisionally viewed as an object of purification, and humans' place and interactions in that world.
Thorough understanding of the structures and functions of conventional reality (saṃvṛti-satya) is considered here indispensable for the realization of ultimate reality (paramārtha-satya), or Buddhahood. Since the earliest period of Buddhism, Buddhists' investigation of the world has been based on their understanding of nature as an orderly system governed by discernible causal laws. This same theoretical basis of investigation also permeates the discussions of the universe and the individual in the Kālacakratantra. An analysis of this tantra and its related literature indicates that the primary goal of the tantric Buddhist investigation of the natural world is to discover the causal factors operating within the universe as macrocosm and within the individual as microcosm.
The secondary goal is to demonstrate the correspondence between the universe and the individual by identifying the properties of the external physical universe in the body of the individual.  This goal reflects the Kālacakra tradition's intent that its very presentation of Buddhist scientific truths be nondual, that is, without drawing an absolute distinction between subject and object. The tertiary objective of the Buddhist tantric scientific investigation is to ascertain the properties of the cosmos and the individual as mere appearances invoked by the power of the individual's habitual propensities. Finally, the ultimate aim is to see things as they are (yathā-bhūta) by
means of acquiring direct knowledge of the nature of reality. Seeing things as they are means perceiving the illusory nature of conventional reality and realizing the nonduality of conventional and ultimate realities. The nature of this nonduality is that conventional reality, although manifesting as the universe, has the form of emptiness (śūnyatā-rūpiṇī, and emptiness has the form of conventional reality (saṃvṛti-rūpiṇī  The realization of the fundamental nonduality of the conventional and ultimate realities and the contemplative path to that realization are the chief topics of the other three chapters of the Kālacakratantra, called respectively the “Initiation, ” “Sādhana, ” and “Gnosis. ”
An analysis of those three chapters indicates that this Buddhist tantric path of actualizing Buddhahood is structured on two theoretical grounds. One is a theory that the universe is contained within the body of the individual as demonstrated by the diverse disciplines of Buddhist natural sciences; and the second is that the natural world as we experience it and explain it through scientific analysis is already nirvāna but needs to be recognized as such. Thus, in the context of Buddhist tantric soteriology, the proper understanding of the conventional world that is the object of purification, the genuine practice of the Buddhist tantric path that is the means of purification, and the authentic actualization of Buddhahood, which is the result of that purification, are directly contingent upon adequate knowledge of the Buddhist natural and social sciences.
The concept of science in the Kālacakratantra is indicated by the Sanskrit word vidyā, meaning “knowledge. ” Already in some of the early Buddhist expositions on vidyā, the term signifies more than knowledge regarding the Four Noble Truths. In the Nettipakaraṇa,  the definition of vidyā includes such concepts as investigation (vicaya), scrutiny or observation (upaparikkhā), and correct views or theories (sammādiṭṭhi). Thus, from early times, Indian Buddhists have recognized the relevance of rational and empirical methods in their studies of the natural world and human thought and relations. However, just as the Western concepts of religion and philosophy do not clearly apply to Buddhism as a whole, so too the Western concept of science does not directly correspond to the phenomenon of Buddhist science.
There are several critical reasons for that—namely, Buddhist science is characterized by widely known and used contemplative and introspective methods of scientific investigation,  its application of extrasensory perception as one of the means of scientific verification, the difficulty of demonstrating the knowledge acquired by contemplative means, and its goal of progress toward, not unprecedented knowledge, but knowledge previously acquired by Buddha Śākyamuni and other Buddhist contemplatives. Nevertheless, I think the term “science” is justified here for several reasons.
First, in Buddhist science there are working hypotheses that are tested by means of experience and that are capable, in principle, of being refuted experientially. Moreover, the conclusions drawn from experience are formulated as rational theories that are internally consistent and make intelligible a wide range of phenomena. In light of the Kālacakratantra's classification of reality into the provisional and ultimate, this tantric system speaks of two types of science (vidyā).  The first type of scientific knowledge is knowledge of conventional reality, which is acquired by means of investigation. As such, it is described as perishable scientific knowledge (kṣara-vidyā), since it is provisional and highly subjective.  It is subjective in the sense that it is affected by the habitual propensities of saṃsāra, which are nothing
other than the measure of the habitual propensities of one's own mind. Scientific knowledge of conventional reality is provisional also due to its being perceptual and conceptual. The verification of provisional scientific truths is based on the sensory perceptions and on inference based on perceptual experiences; but one's perceptions and conceptions of the world are said to depend on the power of one's own merit, or virtue (puṇya). 
Scientific knowledge of conventional reality is also provisional due to its being characterized by a series of momentary cognitions that arise and cease with the arising and ceasing of cognized impermanent phenomena. A transmigratory mind, which observes conventional reality, is momentary because to that mind phenomena appear to arise, remain, and cease in separate, consecutive moments. Such a mind does not perceive the unity, or simultaneity, of the moment of the phenomena's arising, remaining, and ceasing.  Thus, as the mind perceives conventional reality, it discriminates the moments as one and many, and consequently, it discriminates all other phenomena as separate from one another, since they appear to arise and cease in their own separate times. This discriminatory, dualistic manner of perceiving the conventional world as a multiplicity of temporal phenomena is seen as the most prominent characteristic of provisional scientific knowledge. The Vimalaprabhā asserts that this provisional scientific knowledge is inconsequential scientific knowledge to which the human mind is strongly attached.  The Kālacakra tradition affirms that that which is scientific knowledge (vidyā) in terms of conventional reality is ignorance (avidyā) with regard to the ultimate nature of phenomena. 
Ignorance is a habitual propensity of saṃsāra, and it is knowledge accompanied by attachment that often manifests in scientific inquiry as an expectation. Since attachment gives rise to aversion and aversion is of the nature of delusion, provisional scientific knowledge of conventional reality is fundamentally a mental affliction, which subjectively creates all the worlds in every single moment and perceives the world in a biased manner. In contrast, knowledge of ultimate reality, or as-it-is-ness, is viewed as ultimate and imperishable scientific knowledge, because it is not affected by the habitual propensities of saṃsāra. It is a nonconceptual, unmediated knowledge, in which the distinction between the perceiver and the perceived no longer appears. Therefore, this type of scientific knowledge (vidyā) is said to be devoid of an object (analambinī).  It is nonperceptual knowledge, because it is not acquired through the sensefaculties or any conventional means of scientific investigation, nor is it acquired even by means of meditation.
It is free of momentariness, for it does not discriminate moments as one or many. In this way, it dwells in the absence of origination and cessation. Just as saṃsāra is the measure of one's own mind, so too is ultimate reality the measure of one's own mind. Thus, ultimate scientific knowledge is nothing other than self-knowledge, knowledge of the extent of one's own mind. However, even though provisional scientific knowledge of the world is regarded as ultimately incorrect, it is seen as indispensable for gaining eventual knowledge of ultimate reality, which is omniscience, for it facilitates one's understanding of impermanence and emptiness and thereby indirectly brings about the eradication of one's afflictive and cognitive obscurations. Thus, provisional scientific knowledge is seen as an integral part of ultimate scientific knowledge. A careful study of the Kālacakra literature reveals that the scope of science in tantric Buddhism includes not only a wide range of natural sciences but cognitive
sciences as well. Those diverse branches of Buddhist science present systematized knowledge of the nature and composition of the natural world and humans' place and interactions in that world. Adequate knowledge of the Buddhist scientific disciplines and its practical application in an integrated form on the tantric Buddhist path are viewed as highly relevant for one's spiritual maturation and liberation. For that reason, it is thought that the Kālacakratantra practitioner should acquire and cultivate such knowledge and its practical applications for the sake of liberation and for the sake of temporary wellbeing as well. Thus, within the Kālacakra system, all the aspects of the natural world become legitimate fields of Buddhists' scientific investigation, and knowledge of the various scientific fields becomes a significant component of the Buddhist Dharma as the body of verifiable truths.  The Kālacakra literature also demonstrates the ways in which the natural sciences become integrated with cognitive and social sciences on that Buddhist tantric path.
Disciplines classified in the modern world as history, philosophy, fine arts, and psychology are presented in the Kālacakra literature alongside astronomy, cosmology, physics, medicine, biology, pharmaceutics, and alchemy and are jointly utilized in the varied modes of Kālacakratantra practice. The integration of different sciences on this Buddhist tantric path is facilitated by the earlier mentioned tantric view of the nonduality of the individual and the individual's environment. That particular view implies that all psycho-physiological processes of the individual correspond to the physical and socio-historical processes occurring in the individual's environment. For example, the passage of days, seasons, and years corresponds to the passage of prāṇas in the human body; and the individual's spiritual battle with one's own mental afflictions has its external aspect in the religious war of Kalkī with the king of Barbarians in the land of Mecca, and so forth. 
Thus, one may say that in this tantric system, the themes addressed in the Buddhist natural sciences are analogous to the themes of modern science. In all of the above-mentioned disciplines of Buddhist tantric science, the verification of the Buddhist scientific truths appears to be based on the following four means: sensory perceptions, mental perceptions, extrasensory perceptions, and inference. Since earliest times, extrasensory perceptions have been regarded in the Buddhist tradition as a valid means of scientific verification. In its last two chapters, the Kālacakratantra presents rational psychological and physiological conditions for bringing about extrasensory perceptions.
The verification of Buddhist scientific truths concerning the relative nature of the world, as expressed in natural causal laws, is based on all the aforementioned means of verification. Correspondingly, knowledge of relative scientific truths is viewed in this tantric system as perceptual and conceptual and as provisional knowledge of the world as it appears to the dualistic, biased mind. The verification of absolute scientific truth regarding the ultimate nature of the world, as expressed in emptiness, is presented as a form of nondualistic contemplative perception. Knowledge of absolute truth, however, is described as the nonconceptual (avikalpita), unmediated knowledge of all things, in which the distinction between the perceiver and the perceived no longer appears.  An important, common feature of the aforementioned disciplines of Buddhist tantric science is their individual syncretism that permeates the theories and modes of their practical application. The syncretistic nature of Buddhist tantric science, as
evidenced in the Kālacakratantra, stems from the Buddhist tantric view of the commonality of the Buddhists' and heterodox groups' (tīrthika) teachings concerning conventionally existent phenomena. The Kālacakratantra contends that there is no distinction between the Buddhists and heterodox groups with regard to the manner in which conventional reality appears. That view of the commonality of the Buddhists' and heterodox groups' approaches to conventional reality justifies the Buddhist tantric incorporation of specific ideas from other Indian religious and scientific systems and resulted in the syncretism of Buddhist tantric science.
By amalgamating the ideas characteristic of non-Buddhist systems into its own theoretical framework, the Kālacakra tradition attempts to accomplish two objectives: to facilitate its modeling of conventional reality and to convert heterodox groups. In this way, the Buddhist tantric proselytizing efforts significantly contributed to the complex nature of most of the Buddhist tantric scientific disciplines. However, the syncretism of Buddhist tantric medicine appears less related to those efforts, for it stems chiefly from the distinctive Buddhist tantric emphasis on the favorable effects of physical health on one's spiritual development. The Kālacakra tradition gives great importance to the preservation of one's health on the grounds that the achievements of supernormal abilities and liberation are contingent upon proper bodily functioning. Since its earliest stages, the Buddhist tradition has been concerned with medical knowledge and its practical application as supplementary systems of Buddhist learning and religious practice.
The favorable effects of physical health on one's spiritual development are already indicated in the earliest Buddhist Pāli literature. As recorded in the Majjhimanikāya,  Buddha Śākyamuni himself saw health as the individual's finest possession and pointed out the difficulty of reaching enlightenment with an impaired body. For that reason, understanding of the human body and knowledge of maintaining and restoring health have been given soteriological significance in all of Indian Buddhism. However, it is within the context of tantric Buddhism that the preservation of one's health becomes of paramount importance. The Kālacakratantra gives the following reason for that: Firstly, a mantrī should preserve the entire body of the Jina for the sake of siddhis. In the absence of the body, neither any siddhi nor supreme bliss is attained in this life.  Consequently, in the Kālacakra tradition as in other related tantric traditions, Buddhist medicine has been regarded as a major facet of Buddhist Dharma.
The earliest records of Buddhist theoretical and practical approaches to medicine are already found in the Pāli Tipiṭaka. Those records reveal that the early Buddhists' understanding of human anatomy and physiology was generally in accord with that of classical Ārveda, whose basic contents were already formed and well known throughout the Indian subcontinent. The early Buddhist materia medica was also similar to that of the ạyurveda. Nevertheless, early Buddhist records frequently present the knowledge of illnesses and medicinal substances in a less systematic manner and on a more popular level than in the later Ārvedic texts and later Buddhist medical treatises. Also, the ạyurvedic concept of the prāṇa as a support of life is only mentioned in the Buddhist Pāli Canon and not yet developed and medically utilized as it is in the Kālacakratantra. By the time of Mahāyāna Buddhism in India, a rational system of classical
Ārvedic medicine was in general use among Buddhists, and it strongly influenced the scientific framework of later Buddhist medicine.  Several medical treatises— such as Yogaśataka,  Jīvasūtra, Avabheṣajakalpa, Āryājanāmavaṭikā, and Āryamūlakoṣamahauṣadhāvalī  —which the Buddhist tradition ascribes to an author by the name of Nāgārjuna, contain systematized knowledge of selected collections of medicinal formulas, discussions of physiological aspects of diseases, and medical treatments that accord with ạyurveda. The disciplines of alchemy and magic developed alongside the traditional and empirico-rational system of Buddhist medicine. According to a tradition no later than the seventh century ce, those disciplines were already in practice by the time of Nāgārjuna, the alchemist, whose name is mentioned by the Chinese pilgrim Hsüan-tsang. The Rasaratnākara and the Kakṣaputa  have been traditionally attributed to Nāgārjuna, as his writings on alchemy and magic respectively.
The Mahāyāna Buddhist tradition considered Ārvedic medicine, alchemy, and magic as separate but complementary branches of knowledge. It resorted to alchemical preparations, recitation of mantras, and drawing of maṇḍalas as supplementary methods of healing. However, Buddhist tantric medical treatises and the Kālacakratantra literature integrate classical Ārvedic medicine, alchemy, and magic even more strongly into a unique and comprehensive system of Buddhist tantric medicine. The broad scope of the tantric medical system, evidenced in the Kālacakra literary corpus, also encompasses knowledge of preparing incenses and perfumes used for worshipping Buddhas and Bodhisattvas during healing rites. The Vimalaprabhā indicates that the Kālacakratantra's instructions on preparing incenses and perfumes are based on information contained in specialized treatises on the preparation of perfumes and incenses (gandha-śāstra). 
Thus, the manuals on preparing perfumes and incenses form a significant supplementary branch of Buddhist tantric medical literature. As in the earlier Buddhist medical systems, so too in Buddhist tantric medicine, one may find distinctions between magico-religious treatments and rational therapeutics based on induction from observation. In Buddhist tantric medicine, the determination of a medical treatment is contingent upon determining the nature of a disease. Illnesses induced by malevolent spirits (bhūta), also known as nonhuman diseases, and snakebites are commonly treated by means of religious healing rites and mantras.  Mantras are also implemented as the protective, or preventive, methods of counteracting the evil intentions of nonhuman entities.  Likewise, carrying a precious stone of the color red, which belongs to the class of the substances that predominantly arise from the fire-element, is believed to prevent evil spirits from entering one's body, whereas gems that belong to the class of substances that are related to the space-element are said to ward off the cast of an evil eye. 
The Kālacakratantra mentions diverse types of evils spirits and malicious Siddhas who are to be appeased by building specific maṇḍalas outside a village, or under a tree, in a cemetery, in a temple, or at the confluence of rivers, with offerings of delicacies, incenses, perfumes, flowers, candles, praises, and mantras.  The yakṣas, grahas, rākṣasas, piśācas, śākinīs, evil nāgas, who delight in human blood, ḍākinīs, rūpikās, vampire-ghouls feeding in cemeteries (kumbhāṇḍa), protectors of fields (kṣetrapāla), gaṇapatis, pretas, goblins, the lords of ḍākinīs who are accompanied by epilepsy, and malicious Siddhas are all considered to be powerful entities that may cause both illnesses
and great well-being. Therefore, worshiping them is seen as beneficial for the patient's safe recovery. However, the Kālacakratantra warns against the pacification of malevolent spirits when the symptoms of irrevocable death appear, which cannot be warded off by gods, men, or nāgas.  It gives two reasons for this caution.  The first is that religious healing rites are ineffective in such a case, and the second reason is that this situation may create temptation for the tantric yogī to perform the rites simply for the sake of his own material gain, while knowing that they will be of no benefit to the patient. Tantric healing rites also entail the drawing of yantras, the initiation of a patient in a maṇḍala, and ablutions.
For example, a yantra consisting of thirty-four numbers placed within its respective sections should be shown to a pregnant woman when her womb stiffens at the time of childbirth.  Children afflicted by grahas are bathed with the five ambrosias (amṛta): water, milk, sour milk, ghee, honey, molasses, and fragrant water, that are contained within seven unbaked vessels.  At times, certain herbal medications, empowered by mantras, are administered to those possessed by malevolent spirits in order to alleviate the symptoms of afflictions. For instance, in the case of a pregnant woman's sharp uterine pains caused by malevolent entities, the pregnant woman is to be given pounded kustha, us´īra,  kaseru grass, tagara,  blue water-lilly (keśara), and a filament of a lotus with cold water, all of which are consecrated by mantras and vajras. 
Thus, the boundaries between magico-religious and empirico-rational treatments become far less noticeable in Buddhist tantric medicine than in its precedents. In the tantric rites of healing the afflictions caused by nonhuman entities, the magico-religious and empiricio-rational approaches clearly concur. The empirico-rational approach involves diagnosing a disease based upon the observation of its symptoms and the occasions for their occurrence; it establishes the causes of affliction and determines the treatment according to those causes. For example, unpleasant symptoms such as bodily convulsions, sharp pains in the eyes, a yellowish color of the face, arms, and legs, a distinctively yellow color of the urine, fever, vomiting, emaciation, and fainting are described as the symptoms characteristic of a children's disease that are caused by the possession by cruel spirits; and this can be treated by a ritual oblation of the child in the maṇḍala. 
In this way, the empirico-rational approach essentially underlies the magico-religious healing rites. Furthermore, the treatments of other ailments provoked by the disequilibrium of the three humors— wind (vāta), bile (pitta), and phlegm (kapha)—external actions, poor hygiene, inadequate diet, and other similar factors predominantly follow an empirico-rational approach. Thus, the application of slightly warmed akṣobhya in the mouth is administered in the case of an infection of the mouth; anointing of the neck with karkoṭī  lāṇgalī,  and indrī  is applied in the case of the inflammation of the glands of the neck, and so on.  Nevertheless, meditation, visualization of tantric deities, and the recitation of mantras, which are the common healing factors in magico-religious healing rituals, often accompany the administering of medicaments in empirico-rational therapeutics. For example, in the case of the malignant boils in the throat, one abiding in samādhi annihilates strong pains in the following way: while practicing prāṇāyāma, one visualizes in the heart-cakra Viśvamātā appearing as the stainless moon, with her hands in the wish-granting posture and holding a lotus, sitting on a lotus-seat in the vajra posture, and having one face and two arms.  Tantric medicinal mantras mentioned in the Kālacakratantra can be classified Viśvamātā, eliminate, eliminate vajra-like sharp and stingent pains, bring on my forbearance, bring on svāhā, ”  and consecratory mantras such as “oṃ āḥ huṃ take away, take away pains in the womb of such and such person svāhā. ”  In many instances, one mantra can perform more than one function. Thus, in treatments of malignant diseases that are accompanied by fever and pain in the joints, the mantra “oṃ phre vajra” is said to simultaneously empower medicinal herbal ingredients and to protect the patient's bodily cakras. 
The recitation of protective and supplicatory mantras that induce a physiological change by directly influencing the patient's prāṇas may be regarded as an empirico-rational treatment. The Kālacakra tradition's definition of prāṇa as the principal deity of a mantra  and its view of the individual's vajras, or capacities, of body, speech, mind, and gnosis as the source (yoni) of mantras  indicate a close and reciprocal influence between the mantras and the individual's mind and body. In light of this view, one may infer that in the context of Buddhist tantric medicine, the recitation of mantras is utilized as a medical treatment of both the mind  and the body. Although the Vimalaprabhā acknowledges that the power of mantras, medicinal herbs, gems, and other potent substances arises due to the transformation of the mind of the individual who empowers them, it emphasizes that neither mantras nor the empowered substances have limitless powers, since they are not empowered by the mind of the supreme, imperishable gnosis of the Buddha, but by the limited mind of the tantric yogī. 
As its rational methods of cure, Buddhist tantric medicine utilizes the techniques of haṭha-yoga, particularly, the practices of prāṇāyāma and different yogic postures (āsana). For instance, in the Kālacakratantra, the vajra posture (vajrāsana)  is recommended for the elimination of backache, the head-stand posture (śīrṣāsana) for the cure of a disease induced by a disorder of phlegm, the vase technique (kumbhaka) of prāṇāyāma is recommended for the alleviation of abdominal ailments, leprosy, and similar diseases. In the case of leprosy,  the patient is advised to practice the kumbhaka for a period of six months, during which he should not emit semen during sexual intercourse. The Kālacakratantra  also cautions that one should practice prāṇāyāma only until heat in the heart or pain in the head occurs.
If one continues to practice the prāṇāyāma after those symptoms occur, the prāṇa congeals in the navel-cakra, or if unrestrained, it causes death by violently splitting the uṣṇīṣa leaving the body. Sometimes, especially in the cases of the malignant diseases, prāṇāyāma is recommended as an alternative therapy to the application of medicaments. It is chiefly recommended to experienced Buddhist tantric yogīs who are capable of developing profound meditative concentration (samādhi) and who do not always have access to appropriate medication. Thus, to yogīs suffering from a malignant disease of the throat which is accompanied by fever, pains in the joints of the arms and legs, and headache, the following practice of prāṇāyāma is recommended: having entered a windowless house, the yogī should let his arms hang down toward the feet, as far as
The most prevalent empirico-rational therapeutics of Buddhist tantric medicine encountered in the Kālacakra literature are dietary therapy, hydrotherapy, massage, and treatments carried out by means of nasal inhalation and oral consumption of drugs, fumigation, and anointing. For example, everything bitter, combined with three myrobalans (kaṭuka),  is said to obliterate disorders of phlegm, so goat's milk, combined with the three myrobalans, is recommended to those suffering from phlegm-disorders. Since sweet and astringent substances are believed to eliminate bile-disorders, buffalo-cow's milk is administered to those suffering from such an ailment. Camel's milk is administered to those suffering from a disorder of wind, because camel's milk, combined with rock salt (saindhava), becomes an alkaline fluid (ksārāmbu) that removes wind-disorders.
Nasal inhalation of the akṣobhya plant or nasal inhalation of water in the morning is prescribed as a cure for a headache.  In the case of boils, pustules, and similar skin disorders, fumigation with ghee and seasalt wrapped in a cloth and anointing with the sap of arka  are suggested as an effective therapy.  In the case of infections of the ear and eye, the application of warm urine in the ear and of cold urine in the eye is recommended. In the case of sunstroke, the oral ingestion of a decoction containing an equal portion of dhātrī, coriander, and powder of tamarind leaves for three nights is suggested as an effective cure. The curative efficacy of the specific tastes that characterize diverse nutritional, herbal, and mineral ingredients of medicinal preparations is thought to stem from the elements that give rise to the diverse tastes.  Therefore, consuming the appropriate preparations, one supplements the lack of the particular elements in the body that directly caused a disorder of one of three humors.
The aforementioned types of empirico-rational treatments best illustrate the classical Ārvedic and early Buddhist medical heritage in Buddhist tantric medicine. The Kālacakratantra's materia medica is also similar to that of Ārveda and early Buddhist medicine. In addition to herbal and other remedial substances that are wellknown from Ārveda and earlier Buddhist medical treatises, the Kālacakratantra mentions medicinal substances that are not specified in Ārvedic texts or in earlier Buddhist medical works. It is possible, however, that those medicinal substances are known in Ārvedic and earlier Buddhist writings by different names, since the Kālacakratantra occasionally designates the medicinal herbs by terms that seem to be regional folk names—such as “lion's urine” (simhamūtra), “son's hair” (putrakes´a)  — instead of by their generally accepted names. Indian tantric Buddhists, concerned with the preservation of the body, expanded the already existent science of rejuvenation and longevity and structured it as an additional branch of Buddhist tantric medicine. Since Buddhist monastic schools of the eleventh-century India attracted scholars from other countries such as China, Persia, and so forth, one may suspect that tantric Buddhist methods of rejuvenation were influenced to some degree by Taoist and other methods for the prolongation of life. Tantric Buddhists composed various tantric works that deal exclusively with diverse methods of rejuvenation and prolongation of life, which involve the arts of extracting rejuvenating essences and knowledge of performing rituals for longevity. 
In its exposition of Buddhist tantric medicine, the Kālacakratantra indicates the following individual methods of rejuvenation: meditation (dhyāna) that involves bringing the prāṇas into the central nāḍī (madhyamā), practices of prānāyāma, ingestion of the five combined ambrosias (amṛta),  ingestion of life-giving essences extracted from herbs and foods, and ingestion of elixirs produced by means of complex alchemical processes. For example, the kumbhaka, accompanied by the retention of regenerative fluids in sexual union, mentioned earlier with regard to the elimination of leprosy, is also seen as having a rejuvenating power. It is said that if practiced for two years, it eradicates old age and its symptoms. Also, the nasal inhalation of uterine blood and the honey of black bees (keśarājikā), accompanied with meditation, is suggested as a six-month therapy for rejuvenation.
The Kālacakratantra also discusses intricate procedures for preparing tonics, elixirs, and gold, which are also called external elixirs (bāhya-rasāyana) and are regarded by Buddhist tantric tradition as nutrients that induce the attainment of a divine body (divya-deha) that is free of wrinkles and gray hair. Thus, with respect to Buddhist tantric therapeutics, one may draw the following conclusions. Buddhist tantric therapeutics establishes four aims, namely, to prevent and cure disease, to secure longevity, and to bring forth liberation. The first three goals are of a temporal nature. They are not mere ends in themselves but ancillary to the actualization of the ultimate goal, which is enlightenment. In order to actualize its goals, Buddhist tantric therapeutics utilize the syncretized knowledge and practices of tantric yoga, haṭha-yoga, Ārveda, folk medicine, religious esoteric rites of healing and exorcism, the science of distillation, and alchemy into its distinctive Buddhist tantric medical theory and practice. Thus, the immediate objective of the syncretism of the Buddhist tantric medicine is to utilize all available medical knowledge and to provide all possible means of cure and disease-prevention in order to facilitate one's liberation.
However, the syncretism of the Buddhist tantric medicine should not be understood as a reconciliation of disparate views and practices but rather as their synthesis. The Kālacakratantra does not attempt to reinterpret diverse medical theories and practices; it pragmatically juxtaposes them. The Kālacakratantra's medical therapeutics rest on several theoretical grounds that are characteristic of Buddhist tantric medicine as a whole. The primary theoretical basis of Kālacakratantra medicine is tantric Buddhist soteriology that focuses on the intimate relationship among the mind, body, and liberation. On that foundation rests the Kālacakratantra's principal medical theory of the predominant effects of prāṇas on one's mental, physical, and spiritual condition.
To that theory the Kālacakratantra adds the theoretical framework of the secular system of Ārvedic medicine, operating on the presumption that good health is maintained by the equilibrium of the three humors—wind, phlegm, and bile. The fourth element of this theoretical context is the principles of haṭha-yoga, which are based on the view of a causal relationship among bodily postures, breathing exercises, and mental and physical health. Finally, the last theoretical basis of Buddhist tantric medical therapeutics is the premises of folk medicine and occult beliefs concerning bewitchment and spirit possession, according to which, spirits can possess and thereby influence an individual's mental and physical states. Likewise, the theoretical syncretism of Kālacakratantra medicine yields a wide variety of medical treatments. Among the aforementioned medical treatments, the tantric yogic practices of manipulating the prāṇas and retaining regenerative fluids are believed to most directly affect the accomplishment of medical and soteriological ends. Thus, according to the Kālacakratantra, the yogic methods of actualizing supernormal powers (siddhi) are a part of the Buddhist tantric medical theory and practice. The tantric yogic practices of manipulating the flows of the prāṇas and retaining regenerative fluids during sexual intercourse have a dual purpose: spiritual and medical.
When practiced by yogīs endowed with good health, the tantric yogic practices induce spiritual powers and liberation. To those facing premature death, that is, death prior to the age of one hundred, and to those suffering from various diseases—such as abdominal ailments,  asthma, cough, eye-diseases, poisoning, dysuria, and leprosy—they serve as preventive and curative therapeutics. For example, when the signs of untimely death occur, the following yogic practices are sequentially performed. The first is the obstruction of the prāṇas in the left and right nāḍīs; the next phase entails bringing the prāṇas into the central channel nāḍī and making them circulate there for a day; the third phase involves filling one's arms, legs, and fingers with prāṇas; and the final phase involves visualizing the Buddhas' six female consorts with their hands in the protection-mudrā and standing within one's own six cakras.
In the case of the abdominal and other diseases mentioned previously, one is advised to contract the wind of apāna from below the navel and the wind of prāṇa from above. In this way, those two winds colide and cause a strong digestive fire to arise and spread throughout the entire body. It is said that after a month of practicing this yoga, one averts maladies of the liver, spleen, hemorrhoids, asthma, headache, cough, and so on.  Lastly, the syncretism of the Kālacakratantra's medical theory reduced the boundaries between magico-religious and empirico-rational therapeutics. The concurrence of magico-religious and empirico-rational treatments in individual cases was invariably used for two purposes: simultaneously to alleviate the symptoms of the disease and to eliminate the cause of the disease. These multiple aims and means of cure in Kālacakratantra medicine required the incorporation of different sciences as additional branches of medicine. For example, the earlier mentioned science of preparing perfumes and incenses, the science of extracting elixirs from foods and herbs, the science of alchemy, etc. became supplementary fields of medical study. In this way, the syncretism of the Buddhist tantric medical theory and practice broadened the scope of Indian Buddhist medicine as a whole, and it extended the Buddhist tantric framework of theory and practice.
- See Romila Thapar, A History of India, vol. 1, 1966, 253–254.
- Verses 128–147 of the first chapter of the Kālacakratantra give a detailed instruction on building the different types of weapons that should be used by the Kalkī's army in the final battle with the Barbarians in the land of Mecca.
- This view of theological knowledge and scientific learning as complementary is dominant in the Vajrayāna, whereas in the writings of Mahāyāna they are simply compatible rather than complementary.
- See the Samaññaphalasutta of the Dīghanikāya, Thus Have I Heard, 1987, pp. 68–91.
- Bodhicaryāvatāra, 1995, Ch. 5, v. 100.
- The Mahāyānasūtrālaṃkāra, 1970, Ch. 11, v. 60.
- See E. Obermiller, The Jewelry of Scripture by Bu-ston, 1987, p. 29.
- The Mahāyānasūtrālamkāra, Ch. 12, v. 3
- This is not unique to the Kālacakratantra. The earlier medical treatises of Āyurveda— the Suśrutasaṃhitā (first to second centuries ce) and the Carakasamhitā (c. fourth century ce)— assert that the five elements that are present in the body—earth, water, fire, wind, and space— form the entire universe.
- See the Vimalaprabhā commentary on the Kālacakratantra, 1986, p. 43.
- The Nettipakaraṇa, 1962, .
- If one were to ask, “How is introspection scientific in the context of Buddhism?” an answer would be that just as physical phenomena are to be scientifically studied for as far as possible by means of direct observation, similarly, it is true for the first-person mental phenomena. Introspection is widely recognized in Buddhism as the sole means of observing one's own conscious states.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 5, v. 127.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 5, v. 192.
- The Vimalaprabhā commentary on the Kālacakratantra, 1986, Ch. 1, p. 44.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 5, v. 88.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 2, v. 96.
- Already in the early Buddhist Pāli literature, the Buddhist Dhamma was referred to as the verifiable teaching, as the Dhamma that involves one's “coming and seeing” (ehipassika). 21 The Kālacakratantra, Ch. 2, vs. 48–50.
- The Kālacakratantra, Ch. 2, vs. 48–50.
- See the Kālacakratantra, Ch. 2, v. 96, with the Vimalaprabhā commentary.
- The Discourses of Gotama Buddha: Middle Collection, 1992, “With Māgandiya, ” “Major Discourse on the Destruction of Craving. ”
- The Kālacakratantra, Ch. 2, v. 107, lines a—b.
- For more information see Kenneth G. Zysk, Asceticism and Healing in Ancient India, 1991, and the Encyclopaedia of Buddhism, 1963, vol. 1, p. 447.
- According to the Encyclopaedia of Buddhism, 1963, p. 478, some Indian manuscripts ascribe the Yogaśataka to Vararuci instead of Nāgārjuna.
- These five Buddhist medical treatises are included among the twenty-two Āyurvedic works that are incorporated in the Tibetan Tengyur, where they are ascribed to Nāgārjuna. Apart from the Yogaśataka, the Sanskrit originals of the other four treatises are lost.
- According to the Encyclopaedia of Buddhism, 1963, vol. 1, p. 478, an alternative attribution of the Kakṣapuṭa, or the Kacchaputa, is to Nityanāthasiddha
- See the Vimalaprabhā commentary on the Kālacakratantra, 1986, Ch. 2, v. 141.
- Cf. Śāntideva, Śiksāsamuccaya, 1961, pp. 77–78, where Śāntideva advises Bodhisattvas to counteract diseases with the recitation of mantras, along with the usage of medications and water and the offerings of flowers to the image of the Buddha.
- Cf. Maurice Walshe, tr. Thus I Have Heard: The Long Discourses of the Buddha: Dīgha Nikāya: “Aṭānāṭiya Sutta: The Aṭānāṭā Protective Verses, ” 1987, pp. 471–478; the Vinayapiṭaka, vol. 4, 1879–1883. Cf. Śāntideva, Śikṣāsamuccaya, 77, where the author cites the mantras that are set forth in the Trisamayarāja as the mantras to be used for the protection of Bodhisattvas against the Māras and other evil entities.
- See the Kālacakratantra, Ch. 5, v. 187, and the Vimalaprabhā.
- Kālacakratantra, Ch. 2, vs. 154–160.
- According to the Kālacakratantra, Ch. 2, v. 153, the symptoms of irrevocable death are the following: the entire body becomes white, very subtle boils appear, the neck is bent together with the body, blood drips into the mouth, sexual organ, or the rectum.
- The Kālacakratantra Ch. 2, vs. 152–153.
- See the Kālacakratantra, Ch. 2, v. 146, and the Vimalaprabhā
- See the Kālacakratantra, Ch. 2, v. 159, and the Vimalaprabhā.
- The fragrant root of Andropogon Muricatus.
- The fragrant root of Andropogon Muricatus.
- The Kālacakratantra, Ch. 2, v. 149, and the Vimalaprabhā.
- The Kālacakratantra, Ch. 2, v. 152.
- The Kālacakratantra, Ch. 2, vs. 124, 126–127.
- Methonia Superba
- Cucumis Colocynthis, a wild bitter gourd.
- The Kālacakratantra, Ch. 2, vs. 124, 126–127.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 2, v. 128.
- Ibid., v. 130, reads: o phre Viśvamāte vajraka ṃ ṇṭakān nāśaya nāśaya mama śāntiṃ kuru kuru svāhā.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 2, v. 149 reads: om āḥ huṃ amukāyā garbhaśūlaṃ hara hara svāhā.
- See the Kālacakratantra Ch. 2, v. 129, with the Vimalaprabhā commentary.
- See the Vimalaprabhā commentary on the Kālacakratantra, Ch. 4, v. 109.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 4, v. 56.
- See the Vimalaprabhā commentary on the Kālacakratantra, Ch. 3, v. 1.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 5, v. 127.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 2, v. 112, describes the vajra posture in the following way: “The vajra posture entails the left leg on the right thigh, and the right leg on the left thigh. Those two legs have the vajra-connection with the arms being on the top. The right foot is held by the left hand, and the left foot is held by the right hand. ”
- The Sanskrit word kuṣṭharoga, or “leprosy, ” is a general term for the eighteen types of leprosy. Neither the Kālacakratantra nor the Vimalaprabhā specifies whether the term kuṣṭharoga here refers to all of the eighteen types of leprosy or to a specific type of leprosy.
- The Kālacakratantra, Ch. 2, v. 122.
- See the Kālacakratantra, Ch. 2, v. 128, and the Vimalaprabhā.
- Three kaṭukas are three spices: black and long peppers and dry ginger.
- The Kālacakratantra, Ch. 2, v. 124.
- Arka is a tropical and subtropical milky plant that grows in the dry, plain areas. It is also known as Calotropis gigantea, linn., or the milky weed plant.
- The Kālacakratantra, Ch. 2, v. 114.
- The Kālacakratantra, Ch. 5, v. 186, and the Vimalaprabhā.
- The Vimalaprabhā commentary on the Kālacakratantra, Ch. 2, v. 135.
- See the Āyuṣparirakṣānāma, which is preserved in Tibetan translation under the title Tshe bsgrub pa'i gdams ngag ces bya ba and is included in the Tantra commentary (rgyud 'grel) section of the Tengyur (Peking edition of the Tibetan Tripiṭaka, edited by D. T. Suzuki, vol. 69, no. 3236, Tokyo-Kyoto: Tibetan Tripiṭaka Research Foundation, 1955–1961); the Āyuḥsādhana, which is existent only in Tibetan translation under the title Tshe sgrub pa'i thabs and occurs in the Tantra commentary section of the Tengyur (Peking edition of the Tibetan Tripiṭaka, edited by D. T. Suzuki, vol. 86, no. 4863, Tokyo-Kyoto: Tibetan Tripiṭaka Research Foundation, 1955–61); the Āyurbuddhānusmṛti, which is also extant only in its Tibetan translation under the title 'Phags pa sngas rgyas rjes su dran pa and is included in the Tantra commentary section of the Tengyur (P. Cordier, ed. Catalogue du Fonds Tibétain, vol. 2, p. 371, no. 4); the Āyurvardhanīvidhi which is attributed to Candragomin is preserved only in Tibetan translation under the title Tshe 'phel ba'i cho ga in the Tantra commentary section of the Tengyur (TōhokuTeikoku-Daigaku Hōbun-gakubu Tibet-Daizōkyō-So-Mokuroku. Sendai 1932, no. 3666).
- According to the Kālacakratantra, Ch. 2, v. 125, and the Vimalaprabhā, the five internal amrtas— feces, urine, semen, blood, and marrow—when combined with the equal portions of the five external amrtas—sulfur, nectar from black bees, talk, quicksilver, and three myrobalans—soaked for seven days, dried on the heat, and ingested with ghee and honey every day for up to six months, have a life-giving power because they release energy, acid, oil, and salt.
- According to the Kālacakratantra, Ch. 2, v. 111, and the Vimalaprabhā, the maladies of liver, spleen, and hemorrhoids are considered abdominal ailments.
- See the Vimalaprabhā commentary on the Kālacakratantra, Ch. 2, v. 11.
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: Preface
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: Introduction
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Broader Theoretical Framework of the Kālacakratantra
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: A History of the Ṣaḍ-aṅga-yoga of the Kālacakratantra and Its Relation to Other Religious Traditions of India
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Nature of Syncretism in the Kālacakratantra
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Concept of Science in the Kālacakra Tradition
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Cosmic Body
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Social Body
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Gnostic Body
- The Inner Kālacakratantra - A Buddhist Tantric View of the Individual: The Transformative Body