There are two kinds of relations usually defined to analyze given Pali text, namely, word-to-word relations and sentence-to-sentence ones. The former is used to get the syntactic sense of a sentence and has been discussed in Basic / Advanced Relational Grammar. The latter is used to get the accurate picture of logical relations among sentences of a paragraph, a chapter or even a volume. This topic is an introduction to sentence-to-sentence relations.
The Pali term vākya literally means "a sentence", i.e., a self-contained set of words, in which syntactic word-to-word relations can be properly defined without going out of the set. However, it means here an independent unit of content or subject matter, hence the term thematic unit. The smallest thematic unit is a sentence and each of them may combine to form larger ones --- with their extents ranging from two or more sentences up to a whole paragraph or chapter, or even a whole volume.
Many thematic units are marked by certain indeclinables, namely, hi, ca, or pana. They are usually placed immediately after the initial words of their respective sentences. In theory, they are similar to English conjunctions --- they are said to illuminate the thematic relations among thematic units. In practice, however, each of them is used to indicate almost all relations possible; it is almost impossible to rely on them when they are so overloaded.
The actual process is rather the reverse. A thematic marker is only a signal that indicates the necessity to analyze the thematic relation of its HOST unit to the PREVIOUS one. After the analysis has been finished and the relation found out, that relation is used to make a reasonable translation of the marker itself.
The term essential content is used in contrast with the literal content.
For example, a simple sentence counting the Triple Gems as Buddha, Dhamma and Saṅgha is literally different from a whole chapter explaining them in detail one by one; but they are essentially the same in content. Why? Because the subject matter is the same, i.e., the Triple Gems.
The essential content of a thematic unit is related to that of its previous or following one in one of following three ways:
The type of a given thematic unit is defined in reference to its preceding and following ones. For instance, if a unit is an elaboration of the previous one but serves as one of partial content to the following one, it is termed as the unit of both elaboration and partial content. Accordingly, types of thematic units are usually given in pairs; in each pair, each member has its type defined in reference to another.
Depending on the relation of their essential contents, they are divided into three classes.
A. Units of Identical Contents
B. Units of Cause and Effect
C. Units of Ordinary Connection
Note: In each example below, a potential thematic marker is marked as (T.M) and placed as the second word in the subsequent unit. And its translation is also given.
E.g.
B. Sarnath (T.M) is a small village near Benares, a town in the Northeastern part of India. It was known as Migadāya at the time of the Buddha. It was there that the Buddha preached Dhammacakkapavattana Sutta, etc., etc.
(T.M) = " to elaborate OR to give details"
The following unit B is a Unit of Elaboration with reference to A, for it is an elaboration of the word Sarnath mentioned in A. Accordingly, A is termed a Unit of Summarized Content with reference to B.
B. Father (T.M) is mowing the lawn. Mother is preparing the dinner. The son is sweeping the floor. The daughter is cleaning the cupboard.
(T.M) = the same as above
The following unit B is a Unit of Elaboration with reference to A, for it is an elaboration of the working of the family mentioned in A.
Accordingly, A is termed a Unit of Summarized Content with reference to B.
E.g.
B. We (T.M) have altogether 15 members of various professions and pursuits.
(T.M) = " to sum up, to summarize"
The following unit B is a Unit of Summarized Content with reference to A, for it is a summary of the description, given in A, of group members.
Accordingly, A is termed a Unit of Elaborated Content with reference to B.
E.g.
B. Just (T.M) as birds come to a tree full of fruits for a good meal, they moved to town hoping for an easy and happy life.
(T.M) = " to explain OR to make lucid"
The following unit B is a Unit of Illuminated Content with reference to A, for it is an explanation of how that couple moved to town.
E.g.
B. The (T.M) saying goes, " When there’s a will, there’s a way."
(T.M) = " it is true"
The following unit B is a Unit of Confirming Content with reference to A, for it quotes a popular proverb to confirm the prospect of passing the examination.
Accordingly, A is termed a Unit of Doubtful Content with reference to B.
The following unit B is a Unit of Confirming Content with reference to A, for it gives the circumstantial evidence to confirm that he really "wills" to pass the examination.
Accordingly, A is termed a Unit of Doubtful Content with reference to B.
This pair is similar to that of Unit of Elaborated Content followed by Unit of Summarized Content but the concluding part of a topic or chapter or even a whole book is termed Unit of Concluding Content while the rest of the topic, etc. is labeled Unit of Main Content.
E.g.
(T.M) = " Therefore it is known that"
The following unit B is a Unit of Conclusion with reference to A, for it is the conclusion of the premise given in A, i.e., "smoke being seen" .
Accordingly, A is termed a Unit of Premise with reference to B.
(T.M) = " Therefore"
The following unit B is a Unit of Effect with reference to A, for it is the effect of the cause given in A, i.e., " a fire burning in the forest".
Accordingly, A is termed a Unit of Cause with reference to B.
E.g.
B. Smoke (T.M) is seen on the mountain.
(T.M) = " It is known because"
The following unit B is a Unit of Premise with reference to A, for it is the premise of the conclusion given in A, i.e., "Fire being on the mountain" .
Accordingly, A is termed a Unit of Conclusion with reference to B.
The following unit B is a Unit of Cause with reference to A, for it is the cause of the effect given in A, i.e., " Smoke rising into the sky".
Accordingly, A is termed a Unit of Effect with reference to B.
E.g.
B. It (T.M) would be a reflection of the fact that the majority of committee members were against the new leader.
(T.M) = " It would imply that OR Thus"
The following unit B is a Unit of Convincing Implication with reference to A, for it gives the sense which is implied provided the fact given in A is confirmed, i.e., "If the majority of committee members were absent at the meeting" . (Note that B is an indirect verification of A)
Accordingly, A is termed a Unit of Confirmable Content with reference to B.
Note on different opinions:
A given unit is labeled a Unit of Convincing Implication if:
E.g.
(T.M) = " The blame here is"
The following unit B is a Unit of Destructive Implication with reference to A, for it gives the improbable content implied provided the fact given in A is confirmed, i.e., "If the subject is a bore" . (Note that B is an indirect negation of A)
Accordingly, A is termed a Unit of Disputable Content with reference to B.
OR .