Furthermore, a conceptual cognition is a conceptually implying awareness that cognizes an audio (category) or meaning/object (category) as suitable to be associated (with each other).
An audio category (sgra-spyi) is the category of the sound of a specific word, such as “mango,” and as a metaphysical entity, is a permanent phenomenon. All instances of the utterance of the word “mango,” in all voices, all volumes, all pronunciation and all accents are members of the audio category “mango.” It is through such categories that you can understand speech. No matter who says a certain word or how they say it, in each case you can understand the sound as being the same word by conceptually cognizing it through the audio category of the word.
Object categories (don-spyi) are mutually inclusive with meaning categories and they too are metaphysical entities. All mangoes, which are the objects that the audio category “mango” refers to or means, are members of the object category “mango.” It is through such categories that you can understand that several items you see in a store are all mangoes.
Audio categories and meaning/object categories are “suitable to be associated with each other” because they may be cognized separately. You might hear many people who have been to India talk about mangoes, but have no idea what that word means, or you might see several of them in the store and have no idea what they're called.
In conceptual cognition, for instance the thought of a mango, either the audio category or the object category “mango,” or both, is the appearing object. Being metaphysical entities, permanent phenomena, categories have no form. To think of a mango, then, requires something with form to represent it – either a mental image of a mango or the mental sound of the word “mango.” Such a mental representation, a mental hologram of a visible form or sound, needs to be specified.
If you wish to specify something precisely so that it will not be confused with anything else, you would say that it is what is left over after the conceptual exclusion of everything it is not. A mango is not an orange, a peach, an apricot, a cantaloupe and so forth. These are all non-mangoes. Upon the exclusion of everything that is not a mango, what is left, or what is isolated, is the opposite of a non-mango. It is nothing other than a mango, which is equivalent to a mango. The exclusion is not an active process of excluding non-mangoes one by one however, it is conceptual. Similarly, if you want to specify a specific mango: it is what is left upon the conceptual exclusion of all other mangoes. Every permanent and impermanent phenomenon can be individually specified by a conceptual isolate (ldog-pa), a “nothing-other-than.”
In conceptual cognition, for instance the conceptual cognition of imagining a mango, the appearing object that arises is the static object category “mango,” which is equivalent to the static conceptual isolate, “nothing other than a mango.” In excluding everything other than a mango, the conceptual isolate leaves in its place a mental representation (snang-ba) of a generic mango that represents all mangoes. This representation, too, is a static phenomenon. It is not a product of causes and conditions; it did not grow on a tree. Static phenomena do not have any form. Therefore, a non-static mental hologram arises in the conceptual cognition to serve as what a generic mango looks like. This mental hologram is called the conceptually implied object (zhen-yul) of the cognition – the “implied object” for short. It is the involved object of the cognition. The conceptual cognition is deceptive because it mixes or conflates and confuses the category “mango” with this mental hologram of a generic mango, as if all mangoes look like that.
Buddhas do not have conceptual cognition. They know what things conventionally are and what the sounds of words mean without needing to cognize them through categories. Buddhas know everything non-conceptually with bare cognition.
When divided, there are two (types): (1) conceptual cognition that accords with fact and (2) conceptual cognition that does not accord with fact.
Thinking of a clay jug in terms of the category “clay jug” is non-distorted. It is a conceptual cognition that accords with fact (rtog-pa don-mthun). This is true also of your conceptual cognition of the selflessness of persons that arises from inferential cognition. But imagining a rabbit horn, a permanent sound or a permanent, partless, independently existing self of a person, on the other hand, is distorted. It is a conceptual cognition that it does not accord with fact (rtog-pa don mi-mthun).
(There are also) the two: (1) conceptual cognition that applies a name and (2) (conceptual cognition that) applies a fact.
In a conceptual cognition that applies a name (ming-sbyor rtog-pa), a name or word is designated on the object category that is the appearing object and, through that category, is also designated on the mental hologram of an object representing this category and having the defining characteristic of that category. Through such a conceptual cognition, the name or word can also be designated on an external object also having that same defining characteristic. For instance, when you see an object with a fat belly, a flat base and from which water can be poured, you think the name “jug.”
In a conceptual cognition that applies a fact (don-sbyor rtog-pa), the appearing objects are the object category of an attribute (khyad-par, characteristic) – for instance, the object category “breakable objects” – and something having an attribute (khyad-par-can) – for instance “jugs.” Here, however, no words are applied to these categories. The mental hologram that appears in the conceptual cognition is a mental representation of a generic jug. Through the two object categories, you ascribe the attribute of being a breakable object to jugs as represented by this generic image. When seeing a jug, you may conceptualize with such a conceptual cognition that this jug is something that can break, but without verbalizing the thought in your mind. Another example is non-verbally thinking of someone owning a house as a homeowner.
The conceptual cognition that applies the name “jug” to something having a fat belly, a flat base and from which water can be poured is one that applies both a name and a fact. This is because having the name “jug” is also an attribute of an object with a fat belly, a flat base from which water can be poured. Thus, when you see an object having this defining characteristic and attribute and think the word “jug,” you are applying both a word and a fact to it.
A conceptual cognition that applies a name, such as “clay jug,” to something that merely has an attribute of a clay jug, such as being an earthenware object, but which does not have the defining characteristic of one, is not actually a valid applying of a name, even if it thinks “clay jug.” It is a presumptive cognition because something with the attribute of being an earthenware object may also be a clay plate or a clay statue.
There are also the three: (1) conceptual cognitions having reliance on a tag, (2) those that interpolate something extraneous onto something else, and (3) conceptual cognitions of something having an obscured fact. There are many ways to divide them.
 In conceptual cognitions having reliance on a tag (brda-rten-can-gyi rtog-pa), you know something through a tag. A tag (brda, label) is a set of sounds, agreed upon by convention to be a name or word for something and then conceptually applied to an object having the defining characteristic of the word. For instance, you know that four-legged animal with a great hump of flesh on its neck through the tag “brahmin bull” or your five aggregates through the tag “me.” Thus, when your stomach is empty you think, “I am hungry,” imputing the tag “me” on the body consciousness of the physical sensation of hunger as its basis. A more modern example is tagging a specific exoplanet with the name HD 20868 b.
 The Tibetan word for interpolation (sgro-’dogs) literally means tying a feather to a bamboo arrow. Thus, in an interpolating conceptual cognition that adds something extraneous onto something else (don gzhan-la sgro-’dogs-kyi rtog-pa), you tie or superimpose the object category of some extra attribute onto an object that is not qualified by it. For instance, you may think of sound or your conventional “me” as something permanent. As permanence does not apply to what you are ascribing to, such thoughts are conceptual distorted cognitions as well.
The opposite of interpolation is repudiation (skur-’debs). With it, you deny qualities of an object that pertain to it. Thus, instead of thinking of sound as permanent, you would deny that it is impermanent. Interpolation and repudiation prevent you from cognizing a middle path of the actuality of things.
 In a conceptual cognition of something having an obscured fact (lkog-du gyur-ba’i don-can-gyi rtog-pa), you mix an object with one of its obscure attributes that you have not apprehended explicitly through bare cognition. For instance, if there is a man hiding behind a house and you have not seen him, but someone tells you he is there, you come to know something that is not obvious when you look at the house. Likewise, when you gain a conceptual understanding from inferential cognition that sound is impermanent or that your conventional “me” is devoid of existing as a permanent, partless, independently existent soul, you also know something that is not obvious to your bare cognition. In such a conceptual cognition, you mix the object category of an obscure attribute, such as impermanence, with an object qualified by it, such as sound.
In addition, there are the three (types of) conceptual cognition of (1) what has been listened to, (2) (what has been) thought about and (3) (what has been) meditated upon. The meaning of each in turn is the conceptually implying awareness (1) that takes (its object) by means of merely an audio category, (2) that has found certainty (about it) from having thought about its meaning and (3) that is in an upper state (of samsaric existence) from having familiarized oneself further and further with a meaning that has arisen from thinking.
Your teacher tells you about the selflessness of persons. Based merely on having heard the sound of the word “selflessness,” you now can remember the term through the audio category “selflessness of persons,” but without an object/meaning category of its meaning. When conceptually you are aware of the term “selflessness of persons” in terms of an audio category alone, then you have the conceptual cognition of it that arises from listening (thos-byung rtog-pa). This is also an example of a presumptive cognition of something true to be so for a correct reason, but without knowing why.
When you have thought about the meaning of the words you have heard through the use of valid logical arguments such as inferential cognition, you will gain a confident conceptual or intellectual understanding of what the “selflessness of persons” means. You will then have the conceptual cognition of it that arises from thinking (bsam-byung rtog-pa). This will be through the medium of an object/meaning category (don-spyi) based on understanding.
Through repeated inferential cognition, you will gain a thorough familiarity with the accurate meaning of the selflessness of persons. When you have achieve, in this way, a stilled and settled state of shamatha, you have attained a mind on the plane of ethereal forms (form realm) – one of the upper states of samsaric existence (gong-sa) – and a conceptual cognition that arises from meditation (sgom-byung rtog-pa).
Once you have achieved a state of shamatha focused like this on the selflessness of persons, you then need to join it with an exceptionally perceptive state of vipashyana focused on the same object. If, in addition to the network of deep awareness (ye-shes-kyi tshogs, collection of insight) you have built up from such meditational practice as this, you have also built up a vast network of positive force (bsod-nams-kyi tshogs, collection of merit) from having done many constructive deeds with pure motivation over a long period of time, you will then, as a result, achieve yogic bare cognition focused non-conceptually on the selflessness of persons. This comes about not mystically through a leap of faith, but simply through a process of cause and effect. Your joined pair of conceptual shamatha and vipashyana will automatically become non-conceptual as a yogic bare cognition. With this achievement, you become an arya, a “noble one.”
The Number of Valid Ways of Knowing
The types of distorted conceptual cognitions that have arisen concerning how many (distinct ways constitute) the count of (types of) valid cognition are as follows. The Charvakas and Jains accept only one valid way of knowing, namely (1) bare cognition.
In not accepting inferential cognition as valid, but only bare cognition, the Charvakas and Jains assert that you can only know things that are obvious (mngon-gyur). If you cannot directly see something or hear it and so forth, they say you cannot know it.
The Samkhyas assert that there are three (types of) valid cognition: (1) bare cognition, (2) inferential cognition and (3) knowing something through verbal indication.
When you understand what someone means by what they say or you learn something that is true by reading it in a text of scriptural authority or hearing it explained by someone trustworthy, you have validly known something through verbal indication (sgra-byung tshad-ma). The Sautrantikas classify such knowledge under inferential cognition, but the Samkhyas (grangs-can-pa) and many other non-Buddhist schools classify this as a separate valid means of knowing.
Included in this category is not only the knowledge of what someone means when you hear the person speaking in the next room, for instance, but also knowing that the person is there. However, according to the Buddhist explanation of the Sautrantikas, you can apprehend such knowledge implicitly when you have bare auditory cognition of their voice.
The Nyayas accept four: in addition to these three, (4) comprehension of an analogous example.
 You have never seen a zebra. You go to a zoo and see an animal that looks like a mule but has black and white stripes. You know what a mule is and, by its analogy, you know that this strange animal is not a mule. This is cognition of something through comprehension of an analogous example (dpe-nyer ’jal-ba), accepted by the Nyaya (rigs-can-pa) school as a valid means of knowing. You do not exactly know what your object is, but by analogy with other objects that you do know, you can identify what it is not.
The (Bhatta) Mimamsakas claim that the number is definitely only six: these four plus (5) valid cognition through implication and (6) validly cognition of non-existence.
The followers of the Mimamsaka master Kumarila Bhatta assert two further valid ways of knowing.
 The fat man Devadatta does not eat during the day. Because Devadatta is fat and because people must eat in order to be fat and can do so during either the day or the night, you validly know by implication (don-gyis go-ba’i tshad-ma), or disjunctive reasoning, that Devadatta must eat at night. Another example is you know someone is in your two-room house, but you do not see the person in the front room. By implication or a process of elimination you know they must be in the back one.
 There are four types of non-existence (med-pa): antecedent non-existence (snga-na med-pa), perished non-existence (zhig-nas med-pa), mutual non-existence (phan-tshun med-pa) and absolute non-existence (gtan-nas med-pa). The Mimamsakas (rgyal dpog-pa) say that there is a separate means of cognition for validly knowing such non-existences (dngos-po med-pa’i tshad-ma). For instance, when you see milk you can know of the antecedent non-existence of yogurt in it, that is the yogurt’s not yet being in the milk before it has curdled. Later, when you see the yogurt, you know of the perished non-existence of the milk in it, for once it has curdled the milk is no longer there. When you know of the mutual non-existence of a horse in a bull, you see that a bull is not a horse and a horse could not be a bull, for these two are mutually exclusive. When you see a rabbit’s head and know of the absolute non-existence of a rabbit horn on it, you know of the non-existence of something that never existed, does not exist now and can never exist. Although you might fantasize and see a mental image of a goat horn on a rabbit’s head, you cannot possibly imagine a rabbit horn there, because there is no such thing.
The followers of the Charaka (Samhita) assert that the number is definitely eleven. To the above six they add valid cognition through (7) conjunctive reasoning, (8) non-perception, (9) tradition, (10) inclusion and (11) intuition.
The Charaka Samhita (Charaka Compilation), one the two classic source of Ayurvedic medicine, compiled around 200 BCE, asserts five addition types of valid cognition in conjunction with diagnosis of diseases.
(7) With valid inferential cognition, you use analytic reasoning to infer the cause from an effect, for instance where there is smoke there must be fire. The reverse of this is to know something by conjunctive reasoning (rigs-pa), which is to deduce the effect from the conjunction of several causes. An example is where there is fire and burning fuel there must be smoke. With analytical reasoning, then, you reason backwards from an effect to its cause; with the latter you reason forwards from a cause to its effect, based on experience of the world.
(8) If you do not perceive something when if it were there you would, then you know by non-perception (mi-dmigs-pa) that it is not there. For instance, you can know of the absence of horns on a rabbit’s head by your non-perception of them, because if they were there you would surely see them. This is different from simply knowing the absolute non-existence of rabbit horns, where you know something because of the absence of an object. Here you know something because of the absence of a valid means of cognizing it.
(9) When you know something by tradition (zhes-grags-pa), you believe something to be true because everyone else does. An example is knowing that a certain tree contains a spirit because all your ancestors and everyone in your community believe it does. Also, you know by tradition to shake hands with your right hand, and to feed a cold and starve a fever.
(10) When you know something by inclusion (srid-pa), you know about the individuals included in a group by knowing about the group itself. An example is knowing that there are at least ten people in the classroom when you are sure there are fifty, or that a certain person is Japanese because you know he is a member of a Japanese delegation to a conference.
(11) If for no apparent reason you have a feeling that your mother will visit you today and she actually does, then you knew she was coming by intuition (snyam-sems-pa). Although such cognitions do occur, they are unreliable and usually a form of wishful thinking. It is by coincidence that they are true, because more often than not, unless you have achieved the higher attainments of absorbed concentration, your expectations or predictions are false.
Our own tradition is that it is definite that there are only two: (1) bare cognition and (2) inferential cognition.
The reason there are only these two is because there are only two kinds of validly knowable or validly cognizable things – objective entities and metaphysical entities. The former are objects that are obvious and can be apprehended explicitly through bare cognition. The latter are either obscure, such as the impermanence of sound, or extremely obscure, such as the fact that wealth is the result of generosity practiced during previous lives. Such things cannot be apprehended explicitly through bare cognition, although by aryas they may be implicitly so perceived. Ordinary people (so-so’i skye-bo) – those who are not yet aryas – know them through inferential cognition and thus it is necessary for there to be only two distinct valid ways of knowing. To differentiate more as separate methods is superfluous.
Concerning this, the definition of a valid cognition is a fresh, non-fraudulent awareness. When divided, there are two (types): (1) valid bare cognition and (2) (valid) inferential cognition. From another (point of view), there are (another) two (types): (1) valid cognition that determination (of what its object is) is self-induced and (2) (valid cognition) that determination (of what its object is) must be induced by another (cognition). And from the point of view of etymology, there are three (valid sources for knowing something): (1) valid people, (2) (valid) speech and (3) (valid) cognition.
You may know something validly by relying on either valid persons, valid speech or valid cognition. A valid person is a Buddha. Valid speech is his teachings, such as those in the first turning of the wheel of Dharma concerning the four noble truths. The four are the truths of suffering, its cause, its cessation and the pathway mind leading to this. Reliance on such persons or speech will lead you to valid knowledge. You will attain this as well through the valid cognitions of bare cognition and inferential cognition.
These three types of knowing something are valid in the sense that they arise from valid sources. But since your cognition of what Buddha has said may be presumptive or non-determining, these are said to be valid only in an etymological sense and not in an actual one.